某DNA分子中有脱氧核苷酸4000个，已知腺嘌呤和胸腺嘧啶之和占碱

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问题单项选择题

某DNA分子中有脱氧核苷酸4000个，已知腺嘌呤和胸腺嘧啶之和占碱基总数的60％，那么该DNA分子连续复制2次所需要的游离鸟嘌呤脱氧核苷酸分子数是（）

A.800个

B.1600个

C.2400个

D.3200个

答案

参考答案：C

阅读理解

阅读理解，判断正误，对的用“T”，错的用“F”。

This is my study. ICs very nice. My desk is red. My chair is red, too. You can see some books

in the bookcase. My school bag is on the bed. Look! What's that on the desk? Oh, it's my family

photo. The man in brown (穿棕色衣服) is my father. The woman in red is my mother. The girl in

white is me.

( )1. My desk is yellow.

( )2. My chair is red.

( )3. The photo is in the bookcase.

( )4. You can see a telephone on the desk.

( )5. The girl in white is me.

单项选择题

The first treatment given to a person overcome by benzene vapor should be to（）.

A.remove them to fresh air

B.flush their face with water for about 5 minutes

C.stand them up and walk them around

D.remove their clothing and wrap them in blankets