题目内容

1,2-二甲基环丙烷有几个立体异构体?( )

A. 无立体异构体
B. 二个,一对对映体
C. 三个,一对对映体和一个内消旋体
D. 四个,二对对映体

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听力1I. Understanding Long ConversationsDirections: In this section you’ll hear a long conversation or conversations. Listen carefully and choose the best answer to the questions you hear.(5 points)1.[音频]

A. She forgot most of her English.
B. She returned to the regular class.
C. She missed her best friend a lot.
D. She became sad about her studies.

2.

A. Because her English was very good.
Because she had been in the wrong class.
C. Because she wanted to study online.
D. Because she didn't like the regular class much.

3.

A. It was exciting.
B. It was challenging.
C. It was rewarding.
D. It was frustrating.

4.

A. She caught up with other students in the class.
B. She managed to be at the top of the class.
C. She had to be sent back to the regular class.
D. She failed in the final exam despite her efforts.

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