Official 19 Lec 2
答题结果:0/6
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Question 1 of 6
What is the lecture mainly about?

A.

Recent advances in technology used by astronomers

B.

How radio astronomy has led to advances in communication technology

C.

Important discoveries made by radio astronomers

D.

Difficulties astronomers have in observing the universe

我的答案:

正确答案:D

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