WHY DOES THE AUTHOR MENTION "COSMIC RAYS"

Câu 4.

Why does the author mention "cosmic rays"?

A.

To explain the abundance of hydrogen

B.

As an example of an unsolved astronomical

in the universe puzzle

D.

To explain how the universe began

C.

As part of a list of things containing

helium

C - Trả lời C ID:316539 (0) Lời giải & Bình luận