Question:
Use evidence from the fact that being exposed to heat can cause erosion of rocks to answer the following question. "If a rock has been exposed to prolonged heat, what might the effect be?"

Answer:
Erosion

Question:
Use evidence from the fact that as the smoothness of something increases , the friction of that something will decrease when its surface moves against another surface to answer the following question. "As an airboat moves from grass to water it will"

Answer:
speed up

Question:
Use evidence from the fact that a computer controls a robot to answer the following question. "What is essential for a robot to possess to walk up a flight of stairs?"

Answer:

electricity