马和豚鼠体细胞具有相同数目的染色体，但性状差异很大，原因是

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问题选择题

马和豚鼠体细胞具有相同数目的染色体，但性状差异很大，原因是 [ ]

A．生活环境不同

B．DNA分子中碱基对排列顺序不同

C．DNA分子中碱基配对方式不同

D．着丝点数目不同

答案

答案：B

填空题

单词填空。根据下列句子及所给汉语注释，写出各单词的正确形式，每空一词。

1. Many people came to the airport to wait for the famous actor's (到达).

2. (平静下来) down. There's nothing to get excited about.

3. I enjoyed my job at the (开始), but I'm bored with it now.

4. Paper catches fire (容易地).

5. Millie always eats cream cakes. She's (肥胖的) than before.

6. He's very (好看的) but not smart at all.

7. It would be a great (损失) to the school if you left.

8. My mother often (鼓励) me to speak English every day.

9. A spider (蜘蛛) landed on her hand and she (尖叫).

10. There was heavy (交通) on the roads this morning.

问答题论述题

从切身体会谈谈家庭因素与家庭教育的关系。