Problem:OPTIONS:
- energy
- carbon
- heat
- earthquakes
- air
- oil
- O2
- water

You are presented with the quiz "Combustion is used to produce what" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "burning wood is used to produce heat" and "combustion-related, motor vehicles, wood burning, open burning, industrial processes". So, what's the best answer to the question?
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A: heat

Problem:OPTIONS:
- body
- muscle
- state
- a path
- ligt
- a fish
- liquid
- CO 2

You are presented with the quiz "Endocrine hormones travel through the what in something that runs like water?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "endocrine hormones travel throughout the body in the blood" and "and blood, blood runs like water". So, what's the best answer to the question?
****
A: body

Problem:OPTIONS:
- dangerous
- parasitic
- horses
- meiosis
- more abundant
- graptolites
- homogenous
- phytoplankton

You are presented with the quiz "What can the phylum Nematoda be?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "roundworms may be free-living or parasitic" and "roundworms make up the roundworm phylum, Nematoda". So, what's the best answer to the question?
****
A: parasitic

Problem:OPTIONS:
- animals
- horses
- Sea World
- parasites
- bacteria
- fur seals
- boats
- dolphins

You are presented with the quiz "What mainly lives in shallow and coastal waters?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "marine species live mainly in shallow coastal waters" and "marine dolphins are endangered by fishing nets, speedboats, and pollution". So, what's the best answer to the question?
****
A:
dolphins