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

[EX Q]: People stopped adding lead to gasoline because of environmental pollution.
[EX A]: Why did people stop adding lead to gasoline?

[EX Q]: 40 m/s north of the following represents the velocity of a moving object.
[EX A]: Which of the following represents the velocity of a moving object?

[EX Q]: Polymers, ceramics, adhesives, coatings, and liquid crystals are examples of materials recently discovered or developed by chemists type of scientists.
[EX A]:
Polymers, ceramics, adhesives, coatings, and liquid crystals are examples of materials recently discovered or developed by what type of scientists?