*Question*
Answer the following question given this paragraph: All alkali metals are very soft and can be cut easily with a knife. Due to their high reactivity, they must be stored under oil to prevent them from reacting with oxygen or water vapor in the air. The reactions between alkali metals and water are particularly vigorous and include the rapid production of large quantities of hydrogen gas. Alkali metals also react easily with most nonmetals. All of the alkali metals are far too reactive to be found in nature in their pure elemental form. For example, all naturally occurring sodium exists as a compound, such as sodium chloride (table salt). Q: The reactions between alkali metals and water are particularly vigorous and include the rapid production of large quantities of what gas? Choices: - helium - oxygen - carbon - hydrogen A:
**Answer**
hydrogen

*Question*
Answer the following question given this paragraph: 20.3 Terrestrial Biomes Earth has terrestrial and aquatic biomes. Aquatic biomes include both freshwater and marine environments. There are eight major terrestrial biomes: tropical rainforests, savannas, subtropical deserts, chaparral, temperate grasslands, temperate forests, boreal forests, and Arctic tundra. The same biome can occur in different geographic locations with similar climates. Temperature and precipitation, and variations in both, are key abiotic factors that shape the composition of animal and plant communities in terrestrial biomes. Some biomes, such as temperate grasslands and temperate forests, have distinct seasons with cold and hot weather alternating throughout the year. In warm, moist biomes, such as the tropical rainforest, net primary productivity is high as warm temperatures, abundant water, and a year-round growing season fuel plant growth. Other biomes, such as deserts and tundra, have low primary productivity due to extreme temperatures and a shortage of water. Q: Terrestrial biomes are associated with land, while aquatic ones are associated with what? Choices: - plants - air - blood - water A:
**Answer**
water

*Question*
Answer the following question given this paragraph: There are sometimes signs that a large earthquake is coming. There may be small quakes, called foreshocks . These can occur a few seconds to a few weeks before a major quake. Unfortunately, foreshocks are not very useful for predicting large earthquakes. Many quakes do not have foreshocks. Also, small earthquakes are not necessarily followed by a large earthquake. Q: A small quake preceding a large quake is called what? Choices: - aftershock - warning shock - preshock - foreshock A:
**Answer**
foreshock

*Question*
Answer the following question given this paragraph: Reptiles are a class of ectothermic, tetrapod vertebrates. They have several adaptations for living on dry land, such as tough keratin scales and efficient lungs for breathing air. They also have a three-chambered heart and relatively well-developed brain. Q: How many chambers are in a reptiles heart? Choices: - ten - two - five - three A:
**Answer**
three