instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Mollusks live in most terrestrial, freshwater, and marine habitats. However, the majority of species live in the ocean. They can be found in both shallow and deep water and from tropical to polar latitudes. They have a variety of ways of getting food. Some are free-living heterotrophs. Others are internal parasites. Mollusks are also eaten by many other organisms, including humans. Answer: ocean
answer:
Where do the majority of species live?

question:
Passage: With the naked eye, bacteria just look like a slimy smear on a petri dish. How can we study them in more detail? The invention of the microscope has allowed us to see bacteria, cells, and other things too small to be seen with the naked eye. Answer: slimy smear
answer:
How does the bacteria look when seen with the naked eye?

question:
Passage: Some parasites kill their host, but most do not. It's easy to see why. If a parasite kills its host, the parasite is also likely to die. Instead, parasites usually cause relatively minor damage to their host. Answer: it dies
answer:
What is likely to happen to a parasite if it kills its host?