Earth's atmosphere is held in place by earth's
a. orbit
b. clouds
c. gravity
d. rotation

C. Gravity

Explanation: So earth's atmosphere is held in because of its gravity. Gravity is affected by mass. Take the moon for example, its smaller so the gravity on the moon in a little wonky. The earth is obviously bigger so the gravity on the earth is stronger than on the moon.

Hope I helped!

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