Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Phospholipids are the main component of the cell membrane.

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

Question: Digestion begins in the gastrovascular cavity.

Answer: Where does digestion begin?

Question: Producers in an ecosystem generally get their energy from the sun.

Answer:
Where do producers in an ecosystem generally get their energy from?