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问题 单项选择题

下列关于单倍体的叙述，错误的是（）

A.单倍体体细胞含有一个染色体组

B.体细胞含有本物种配子染色体数目的个体

C.单倍体个体一般是不育

D.单倍体常采用花药离体培养的方式获得

答案

参考答案：A

句型转换

按要求改写下面句子。

1. Help was often given to him by us. (改为主动语态) 

    We often              him            .

2. Maths is more difficult than any other subject. (改为同义句) 

    Maths is the              difficult             all the subjects.

3. I have written to him for a long time. (改为同义句) 

    He ______ ______ ______ me for a long time.

4. I started to study English two years ago. (改为同义句)

    I                         English for two years.

5. We have an English test once a month. (对划线部分提问) 

                            do you have an English test?

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单项选择题

从域名WWW.sina.com.cn可以看出，这个站点是中国的一个( )。

A．政府部门
B．军事组织
C．商业机构
D．教育机构
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