instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Amount of salt are aquatic biomes often classified.
answer:
How are aquatic biomes often classified?

question:
A human cannot survive the loss of the liver of the following.
answer:
A human CANNOT survive the loss of which of the following?

question:
Physical and chemical differences help ecologists distinguish between freshwater and marine types of biomes.
answer:
Physical and chemical differences help ecologists distinguish between freshwater and marine types of what?