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

Q: Filter feeders called rotifers collect digestive and excretory wastes in cloacal bladder primitive organ.

A: Filter feeders called rotifers collect digestive and excretory wastes in what primitive organ?
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Q: Clear mucus is secreted before ejaculation to neutralize acidic urine remaining in the urethra.

A: What is secreted before ejaculation to neutralize acidic urine remaining in the urethra?
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Q: One gram of sugar or starch provides 4 calories of energy.

A:
How many calories of energy does one gram of sugar or starch provide?
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