instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Rod is the general shape of centrioles.
answer:
What is the general shape of centrioles?


question:
In pupa stage of their life cycle do insects begin developing their wings.
answer:
In what stage of their life cycle do insects begin developing their wings?


question:
A glacier leaves behind bare rock when it retreats.
answer:

What does a glacier leave behind when it retreats?