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问题 单项选择题 A1/A2型题

初次妊娠妇女自觉胎动，多数开始于（）

A.妊娠15～17周

B.妊娠18～20周

C.妊娠21～23周

D.妊娠24～26周

E.妊娠27周以上

答案

参考答案：B

解析：初次妊娠妇女妊娠18～20周可自觉胎动，此时用听诊器经妊娠妇女腹壁能听到胎儿心音，每分钟120～160次。

解答题

0.7+3.9+4.3-3.9

99×7.65+7.65

5.1×102

0.78÷2.5÷0.4．
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单项选择题

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

It is more and more usual that users of Information Retrieval (IR) systems must face up to response of hundreds or thousands of (1) documents. A significant proportion of them are moreover (2) or redundant. This is a straight consequence of two well - known facts: the incessant growing of documental databases and the lack of ability of most users to define (3) information needs. In such a framework, further effective retrieval techniques are only part of the solution. Interfaces with alternative ways for organizing and (4) the results returned by a (5) would be of great utility assisting users to find relevant documents. Document clustering may play a central role as an effective technique for organizing query results.

1（）

A．replied

B．retrieved

C．received

D．relied
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