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

[Q]: The love canal tragedy was an infamous example of industrial waste dumping.
[A]: Love canal was an infamous example of what type of pollution?

[Q]: In pupa stage of their life cycle do insects begin developing their wings.
[A]: In what stage of their life cycle do insects begin developing their wings?

[Q]: When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the capillaries.
[A]:
When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the what?