Question: Answer the following question given this paragraph: Grain boundaries. As a polycrystalline material solidifies, grains with irregular shapes form. The interfaces between grains constitute grain boundaries. (Squares represent unit cells within grains. Q: As a polycrystalline material solidifies, grains with irregular shapes form. the interfaces between grains constitute grain what? Choices: - waves - patterns - obstacles - boundaries A:
Answer: boundaries

Question: Answer the following question given this paragraph: All volcanoes share the same basic features. First, mantle rock melts. The molten rock collects in magma chambers that can be 160 kilometers (100 miles) beneath the surface. As the rock heats, it expands. The hot rock is less dense than the surrounding rock. The magma rises toward the surface through cracks in the crust. A volcanic eruption occurs when the magma reaches the surface. Lava can reach the surface gently or explosively. Q: When magma reaches the surface through cracks in the earth's crust, what occurs? Choices: - volcanic explosion - magma eruption - tsunami - volcanic eruption A:
Answer: volcanic eruption

Question: Answer the following question given this paragraph: Crests and troughs are the high and low points of a transverse wave. Q: Crests and troughs are the high and low points of a what? Choices: - darker wave - rupture wave - heat wave - transverse wave A:
Answer:
transverse wave