instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Embryos usually don't survive if they have extra or too few of these genetic units?
answer:
Embryos usually don't survive if they have extra or too few of these genetic units?


question:
Some compounds form rigid frameworks called crystals.
answer:
Some compounds form rigid frameworks called what?


question:
Co2 are carbonated beverages pressurized with.
answer:

What are carbonated beverages pressurized with?