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问题 单项选择题

对生态系统描述不正确的是（）

A.是生物圈内能量和物质循环的一个功能单位

B.是在一定空间范围内，由生物群落及其环境组成

C.生态系统是一个封闭的系统

D.借助于各种功能流（物质流、能量流和信息流）所连接的稳态系统

E.构成生物群落的生物是生态系统的主体

答案

参考答案：E

单项选择题

目前临床广泛使用的尿hCG测定法是（）

A.单克隆抗体胶体金试验

B.ELISA

C.放射免疫试验

D.胶乳凝集试验

E.电化学发光免疫法
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填空题
词语填空
用所给单词的适当形式填空.
order　be　watch　away　close　manner　who　where　unless　but
     It is good __1__ for an Arab to stand __2__ to his friend when they are talking __3__ English people
do not like to __4__ too close to one another __5__ there is a reason. It could be very interesting to
__6__ an Arab and an Englishman talking together. The Arab __7__ is friendly will stand close to his
friend, but the Englishman will move back in __8__ to keep a certain distance __9__.When they finish their
talk, the two may be quite a distance away from the place __10__ they were standing.
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