Answer: C. the motion of a spacecraft under gravitational influence.
Explanation:
A is Metallurgy, B is Biology, C is astro-physics, I am not sure what D is, but it's safe to say it's not physics, E, micro-biology, and the study of radiation. C is the only one involving physics.
There are many types of machine what type well for every day machines like treadmills is sweating, dehydration, loss of calories or fat.
B. How many people were included in the study.
It is an important part of many cells and processes such as amino acids, proteins and even our DNA. It is also needed to make chlorophyll in plants, which is used in photosynthesis to make their food.
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