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

[EX Q]: Lipids are available to the body from three sources.
[EX A]: Lipids are available to the body from how many sources?

[EX Q]: Landslides moving loose rocks downhill process is the best example of a sudden change to earth’s surface.
[EX A]: Which process is the best example of a sudden change to Earth’s surface?

[EX Q]: The cell expels waste and other particles through a process called exocytosis.
[EX A]:
The cell expels waste and other particles through a process called what?