Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: Simple carbohydrates can be classified in terms of chain length. Answer: simple

Output: Which carbohydrates can be classified in terms of chain length?

Input: Consider Input: Passage: Abrasion is another type of mechanical weathering. With abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a slope. Moving water causes abrasion it moves rocks so that they bump against one another ( Figure below ). Strong winds cause abrasion by blasting sand against rock surfaces. Finally, the ice in glaciers cause abrasion. Pieces of rock embedded in ice at the bottom of a glacier scrape against the rock below. If you have ever collected beach glass or pebbles from a stream, you have witnessed the work of abrasion. Answer: mechanical

Output: What kind of weathering is abrasion?

Input: Consider Input: Passage: It is actually the Yellow Christmas tree worm. These animals are colorful, and can be red, orange, yellow, blue, and white. The Christmas tree worm lives on tropical coral reefs throughout the world. The Christmas tree worm's plumes are used for feeding and respiration. These worms use their plumes to catch plankton and other small particles passing in the water. Cilia then pass the food to the worm's mouth. Answer: tropical coral reefs
Output: Where does the christmas tree worm live?