bones,       air pressure,       climate,          atmosphere,

altitude,       carbon dioxide,       anemometer,       aquatic biomes,

arctic air mass,      arteries,       adaptation,       barometers,

biome,       bladder,       capillaries,       blood,       bony fish,     burrows,       canopy,       adapt,       amphibians,       cartilage,      circulatory system,       air mass,      blood vessels,

6. ___________________ are animals that live part of their lives in water and part on land.

2. An ___________________ is a characteristic of an animal that helps it survive.

4. ____________ ____________ is caused by the weight of the air in the atmosphere.

19. ___________________ are underground homes for some small grassland animals, such as gophers.

5. ___________________ is the distance above sea level.

8. ______________ _________________ are areas where plants and animals live in water.

24. Your __________________ ________________ has three parts---the blood, the heart, and the blood vessels.

9. An ____________ ______________ _____________ is a very cold air mass.

10. ___________________ are blood vessels that carry oxygen-rich blood from the heart to the rest of the body.

1. Living things ___________________ when they adjust to life under different conditions.

11. The ___________________ is the air that surrounds Earth.

7. An ___________________ measures wind speed.

12. ___________________ measure air pressure.

3. An ___________ _____________ is a huge body of air that forms above a large area of land or water.

14. The ___________________ stores waste liquid form the kidneys until it can leave the body.

25. ___________________ is formed by the temperature and rainfall patterns of an area.

16. ____________ ______________---arteries, veins, and capillaries---are the tubes through which blood travels.

17. ___________________ are hard tissue that makes up your skeleton.

22. _____________ ______________ is a gas in the air. Plants use it to make food. Animals breathe it out as a waste.

18. ___________ ___________ have skeletons mad mostly of bone.

15. ___________________ is a liquid that travels throughout the body, bringing oxygen to the cells and taking carbon dioxide away.

20. The ___________________ is the top part, or roof, of the rain forest.

13. A ___________________ is a large place with a certain climate and plants and animals adapted to that climate.

21. ___________________ are tiny blood vessels in the human body where the exchange of oxygen and carbon dioxide happens.

23. ___________________ is a tough tissue, like the hard tissue in your outer ear.

condensation,      decompose,    evaporation,      deserts,          coal,

excretory system,    cold front,     electromagnetic spectrum,   compost,

conduction,      exosphere,      continental air mass,     conifers,

contracts,      electromagnetic radiation,      deciduous,      diaphragm,

digestive system,      dinosaurs,      domesticated plants,    evergreens,

electrical energy,      erosion,      convection,     esophagus,

44. The ___________________ is formed by all the different kinds of electromagnetic radiation.

26. ___________________ is a fossil fuel made from dead plants that were buried before they decomposed completely.

27. A ___________ __________ forms when a cold air mass pushes under a warm air mass, forcing the warm air up.

29. ___________________ is the process in which a gas changes into a liquid.

30. ___________________ is the flow of heat through the movement of molecules in a solid object or from one object to an object it is touching.

31. ___________________ are trees and shrubs that hod their seeds in cones. Pine trees and fir trees are both conifers.

32. A ________________ _______ ____________ has low humidity.

33. When something ___________________, its molecules move closer together.

28. ___________________ is natural waste that has decayed into soil filled with nutrients.

34. ___________________ is the circular motion of heat through liquids or gases.

49. The ___________________ carries wastes out of the body.

35. ___________________ trees lose their leaves in autumn and grow new ones every spring. ___________________ forest are forests that have many ___________________ trees.

36. When materials ___________________, they break down into simpler materials.

39. Your ___________________ turns the food you eat into fuel that runs your body.

37. ___________________ are the driest biomes, receiving less than ten inches of rain in a year.

38. The ___________________ is a smooth muscle stretched across the bottom of your lungs. When it contracts, it gets flatter and pulls the lungs down to help you breathe.

40. ___________________ were reptiles that appeared about 230 million years ago. They ruled Earth for more than 140 million years.

41. ___________________ have been kept separate from their wild ancestors and grown under controlled conditions.

42. ___________________ is a form of energy produced by batteries and power plants.

43. ___________________ is all the kinds of energy given off by the sun. The sun is not the only source.

45. ___________________ happens when rain and wind carry away the richest top layers of soil.

46. The ___________________ is the tube leading from your mouth to your stomach.

47. ___________________ is the process in which a liquid changes into a gas.

48. ___________________ are plants that stay green all year.

50. The ___________________ is the topmost layer that is found in Earth's atmosphere.

extinct,     ferns,      generator,      flowering plants,     forecast,

gravity,     fossil,     hurricane,      fuels,      fossils,    gamma rays,

expands,     friction,     humidity,     front,      hybrid plants,

fulcrum,      heart,      forests,       gills,      force,

grasslands,      groundwater,     hard-boiled,    fertilizer,    heat

53. ___________________ are leafy, green plants that grow well in shady, damp places.

51. When something ___________________, it spreads out.

52. ___________________ means that a certain kind of living thing is no longer alive.

54. ___________________ is a special nutrient that is added to soil to make it richer for plants.

55. ___________________ produce seeds in flowers.

56. A ___________________ is a push or a pull that changes the position of an object.

57. To ___________________ is to tell what may happen with the weather.

58. ___________________ are biomes that have many trees growing close together.

60. ___________________ are traces of early life that have been preserved in rocks.

61. ___________________ is a force that resists, or works against, motion between two objects that are touching.

62. A ___________________ is the zone formed where two air masses with different properties meet.

63. A ___________________ is the fixed point around which a lever moves.

64. ___________________ are the shortest waves of energy in the electromagnetic spectrum. They travel through almost any material.

59. ___________________, such as petroleum, natural gas, and coal, formed under the ground from the remains of plants and animals that lived millions of years ago.

65. A ___________________ is a machine that changes mechanical energy to electrical energy.

74. A ___________________ is a dangerous storm that forms over the ocean.

66. ___________________ are special body parts that animals, like fish, use to take in oxygen from the water around them.

67. ___________________ are dry biomes that get more rain than deserts, but not enough steady rain for a large number of trees to grow.

69. ___________________ is formed by precipitation that sinks deep within Earth.

70. ___________________ animals are animals with bones or shells supporting their bodies.

71. The ___________________ is a special muscle that pumps blood throughout the body.

68. ___________________ is a force that pulls objects toward each other. It pulls on any object.

72. ___________________ is energy that moves from a warmer object to a cooler object.

73. ___________________ is the amount of water vapor in the air.

75. ___________________ result when people combine two different plant species.

lungs,    inclined plane,    insects,    minerals,    intestines,

involuntary muscles,    jawed fish,    mammals,     joints,

invertebrates,    kidneys,     kinetic energy,     lever,   meteorologists,

load,    infrared radiation,    machine,   mesosphere,   marine biomes,

jawless fish,     maritime air mass,    light energy,     mechanical energy,

microwaves, mining

76. An ___________________ is a simple machine. It is a slope that makes it easier to lift objects.

88. ___________________ is a form of energy that can travel through empty space and through clear objects.

78. ___________________ are tiny invertebrates with six legs.

79. The walls of small ___________________ soak up tiny pieces of food. The large ___________________ draws water out of the remaining food.

80. ___________________ are animals without backbones.

81. ___________________ are the muscles that move even when your are sleeping.

77. ___________________ is another name for heat energy. It is found just above radio waves in the electromagnetic spectrum.

82. ___________________ can bite and hold food in their mouths.

83. ___________________ have a sucker moth instead of jaws. Examples include lampreys.

85. The ___________________ remove waste from your blood.

86. ___________________ is the mechanical energy in moving objects.

87. A ___________________ is a bar that moves around a fixed point.

89. The ___________________ is the object moved by a lever.

90. The ___________________ are where oxygen is brought into the body and carbon dioxide is removed.

84. The bones in your skeleton are connected at ___________________

91. A ___________________ is a tool that makes work easier.

92. ___________________ are vertebrates with hair on their bodies. They feed milk to their young.

93. _____________ _____________, or saltwater biomes, include all the oceans of the world.

100. ___________________ is taking natural resources like coal and metals from the ground.95. __________________ _____________ is the energy of moving objects.

96. The ___________________ is the layer of air above the stratosphere and below the thermosphere.

97. ___________________ are people who study weather.

98. ___________________ are radio waves used in radar and in some ovens to cook food.

94. A __________________ ______ ___________ has high humidity.

99. ___________________ are metals and shiny stones that are found under the ground.

muscles,     natural gas,     ozone,     natural resources,     pulley,

nectar,     pollen,     nonrenewable resources,     ore,     molecules,

oxygen,     petroleum,     phloem,     plasma,     photosynthesis,

plankton,     nitrogen,     platelets,     polar air mass,     pollination,

radar,     potential energy,     precipitation,     radiation,     pollute,

101. ___________________ are the smallest particles of a substance, such as water.

102. ___________________ allow you to move your bones.

103. ________________ __________ is a fossil fuel that forms underground from petroleum if temperatures are high enough.

104. ________________ _________________ are living and nonliving things found on Earth that help people meet their needs.

105. ___________________ is food for insects made by flowering plants.

106. ___________________ is the most plentiful gas in air.

107. ___________________ _______________ are such things as oil and coal that are present on Earth in limited amounts.

108. ___________________ is rock that contains a large amount of a certain mineral such as iron.

109. ___________________ is one of the gases that make up air. Animals need it to live. Plants give it off as waster.

110. The ___________________  layer in Earth's stratosphere protects us from the sun's harmful rays.

111. ___________________, or crude oil, is a sticky, liquid fossil fuel.

112. ___________________ tissues carry food made by plants during photosynthesis.

113. ___________________ is the process in which plants use sunlight to make food.

114. ___________________ are tiny plants and animals that float at the surface of the ocean.

115. ___________________ is a yellow liquid made mostly of water. It acts as a stream in which the red and white blood cells and platelets float.

116. ___________________ are the smallest of the blood cells. They allow your blood to clot.

117. A _____________ _____________ _____________ is a cold air mass.

118. ___________________ is a yellow dust that flowering plants make to help them reproduce.

119. ___________________ is the process in which flowering plants use pollen to make seeds.

120. People ___________________ the soil, air, and water by placing harmful materials in them.

121. ______________ ______________ is the mechanical energy that is stored in nonmoving objects that can move.

122. ___________________ includes rain and snow.

123. A ___________________ is a simple machine. It is a rope looped around a wheel.

124. From Earth, weather radar tracks the movement and speed of storms.

125. ___________________ is the movement of heat energy through empty space, as from the sun to Earth.

radio waves,    rain forests,    temperature,    red blood cells,

renewable resources,    reproduce,    reptiles,    respiratory system,

runoff,    saliva,    saltwater,    satellites,     savanna,    screw,

sea level,    simple machine,     soft-bodied,    soil,    solar energy,

solar heaters,    sound energy,    species,    stationary front,

tendons,     stomach,     stratosphere,     taiga

126. ____________ __________ are the longest waves in the electromagnetic spectrum. They are used to broadcast radio and television programs.

127. _____________ ________________ are forest biomes that receive from 80 to 200 or more inches of rain a year.

128. ____________ _______________ ___________ carry oxygen from the air you breathe to all the parts of your body. The carry carbon dioxide, or waste gas, that body cells do not need to the lungs.

129. __________________ ________________ are such things as plants and animals that can never be used up if they are used properly.

130. When living things ___________________, they make new living things of the same species.

131. ___________________ are vertebrates with dry, scaly skin.

132. The _____________________ ________________ includes the trachea, lungs, and diaphragm.

133. ___________________ is precipitation that flows on Earth's surface.

134. ___________________ is a liquid made in your mouth.

135. ___________________, like the water in the oceans, contains salt.

136. Form above Earth's atmosphere, weather satellites collect information about the atmosphere and send it back to Earth.

137. A ___________________ is a grassland in Africa.

138. A ___________________ is a simple machine made up of an inclined plane wound around a post.

139. __________ ______________ is where the air meets the ocean.

140. A ______________ _______________ is a machine that does work with only one movement.

141. ___________-______________ animals are animals without bones or shells for body support.

142. ___________________ is the top layer of Earth's surface. It is made of tiny pieces of rocks mixed with natural waste, such as dead leaves.

143. _____________ ______________ is heat energy from the sun.

144. _____________ _____________ capture the sun's energy.

145. _____________ ______________ is a from of energy that can travel through air, water, metal, and other materials.

146. A ___________________ is a group of living things of one kind.

147. A ___________________ ______________ forms when a warm air mass and a cold air mass meet and neither air mass moves.

148. The ___________________ stores food and mixes it with chemicals that break the food down.

149. The ___________________ is the layer of air above the troposphere and below the mesosphere.

150. The ___________________ is one of the coldest biomes. It is an evergreen forest with long winters.

151. ___________________ is a measure of how hot or cold something is.

152. ___________________ are strong, elastic tissues that attach muscles to bones.

thermosphere,    trachea,    windbreaks,    thermometers,

tropical air mass,    tropics,    work,    troposphere,    weather vane,

tundra,    ultraviolet light,    vascular plants,     vertebrates,

visible light,    wheel and axle,    voluntary muscles,    warm front,

turbine,     water cycle,     xylem,     water vapor,     weather stations, veins,     wedge,     white blood cells,     wind,     X-rays,     tornado,

154. The ___________________ is the layer of air above the mesosphere and below the exosphere.

153. ___________________ measure temperature.

155. A ___________________ is a dangerous storm that forms over land.

156. The ___________________ is the main air tube, leading from your nose and mouth to your lungs.

157. A ___________________ __________ ___________ is a warm air mass.

162. ___________________ ______________ is just above visible light in the electromagnetic spectrum. It causes sunburn.

158. The ___________________ are parts of the world where temperatures are warm all year.

159. The ___________________ the layer of air that is closest to Earth's surface.

160. The ___________________ is one of the coldest biomes. For most of the year, the tundra is a frozen grassland.

161. A ___________________ is a kind of giant fan used in power plants to run a generator.

163. ___________________ _______________ are plants that have special tissues called xylem and phloem.

164. ___________________ are blood vessels that carry blood filled with carbon dioxide to the heart.

165. ___________________ are animals with backbones.

166. ___________________ ____________ is the only part of the electromagnetic spectrum that human eyes can see. ___________________ _____________ waves are slightly shorter than infrared waves.

170. ___________________ ____________ is the gas that liquid water changes into when it gains enough heat energy.

167. ___________________ ______________ are the muscles that move your skeleton. You can move them when you want to.

168. A ____________ _____________ forms when a warm air mass pushes up and over a cold air mass.

169. The ___________________ ____________ is the way changes form and moves in Earth's atmosphere and on land.

171. ___________________ _______________ are places where meteorologists set up weather equipment.

177. ___________________ are rows of trees that help block erosion of soil by the wind.

172. A ___________________ ____________ measures wind direction.

173. A ___________________ is a simple machine made up of two inclined planes placed back to back.

174. A ___________________ and ____________ is a simple machine made up of a disk attached to a post.

179. ___________________ are the second sortes waves of energy in the electromagnetic spectrum. They pass through skin and muscle, but are absorbed by bone.175. ___________________ ____________ ____________ act as the body's soldiers against disease. They move to where germs are and work to destroy them.

176. ___________________ is the movement of air.

178. ___________________ is done whenever a force applied to an object causes the object to move in the same direction as the force.

180. ___________________ tissues carry water and nutrients throughout the plant.