Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Input: Consider Input: A penguin must do increase muscle mass before molting.

Output: A penguin must do what before molting?


Input: Consider Input: Phospholipids are the main component of the cell membrane.

Output: What is the main makeup of the cell membrane?


Input: Consider Input: Scientists think protists are the oldest eukaryotes.


Output: What do scientists think are the oldest eukaryotes?