instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
People stopped adding lead to gasoline because of environmental pollution.
answer:
Why did people stop adding lead to gasoline?


question:
Toxins is contained in the skin of brightly colored poison dart frogs.
answer:
What is contained in the skin of brightly colored poison dart frogs?


question:
Wooden board of these is most likely the hardest to bend.
answer:

Which of these is MOST likely the hardest to bend?