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

[EX Q]: The long, threadlike extensions of the nerve cell help transmit nerve impulses.
[EX A]: Which part of the nerve cell helps transmit nerve impulses?

[EX Q]: Environmental changes is most responsible for the extinction of most species of plants and animals that have lived on earth.
[EX A]: What process is most responsible for the extinction of most species of plants and animals that have lived on Earth?

[EX Q]: Wood burning is an example of a different substance being formed.
[EX A]:
Which is an example of a different substance being formed?