Instructions: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
Input: Studies have shown that not only does reproduction have a cost as far as sperm long male fruit flies live, but also fruit flies that have already mated several times have limited amounts of this.
Output:
Studies have shown that not only does reproduction have a cost as far as how long male fruit flies live, but also fruit flies that have already mated several times have limited amounts of this?