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问题 选择题

一种动物体细胞的染色体数为24，该动物体内一个处于有丝分裂后期的细胞，其同源染色体对数和DNA分子个数分别为[ ]

A．12、48

B．24、48

C．24、24

D．48、48

答案

答案：B

填空题

短文填词。

     There are (1)s            students in my group. Sam's birthday is in (2)J           . It's the first (3)m          

 of the year. Ruth's birthday is in (4)M           . It's after Women's Day. Jack was born on (5)J             1.

It's also Children's Day. Will and Tina were born in the (6)t            month-(7)O           . They are proud

(自豪的) they have the same (8)b            as our country. My birthday is in the last month-(9)D           .

(10)W            is your birthday? Can you tell us?

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单项选择题

确定系统边界属于数据库设计的（）阶段。

A．需求分析 

B．概念设计 

C．逻辑设计 

D．物理设计
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