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

[EX Q]: When a sperm penetrates the egg, it triggers the egg to complete meiosis.
[EX A]: When a sperm penetrates the egg, it triggers the egg to complete what?

[EX Q]: The bird ancestor that lived in trees developed wings, which is commonly associated with birds.
[EX A]: The bird ancestor that lived in trees developed what feature commonly associated with birds?

[EX Q]: Nonmetals have the highest attraction for electrons.
[EX A]:
What elements have the highest attraction for electrons?