Earth is approximately spherical in shape like all planets and stars. Earth is composed mostly of rock. Three-fourths of its surface is covered by a relatively thin layer of water (some of it frozen), and the entire planet is surrounded by a relatively thin blanket of air.
Answer:
a
Explanation:
its more direct..it makes more sense
Answer:
provides protection to the valves and heart chambers.
Explanation:
I believe thats true.
People with cancer get radiation treatments to treat their cancer, it doesnt cure them but it does help treat the cancer.
