instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
The majority of arthropods live on land.
answer:
Where do the majority of arthropods live?


question:
2 hydrogen, 1 oxygen atoms combine to make up a molecule of water.
answer:
What atoms combine to make up a molecule of water?


question:
After the blood in the pulmonary capillaries becomes saturated with oxygen, it leaves the lungs and travels to the heart.
answer:

After the blood in the pulmonary capillaries becomes saturated with oxygen, it leaves the lungs and travels where?