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问题 选择题

心脏中房室瓣的功能是防止（　　）

A．心室的血液倒流回动脉

B．心房的血流倒流回心室

C．动脉的血液倒流回心室

D．心室的血液倒流回心房

答案

心房与心室之间、心室与动脉之间，都有能开闭的瓣膜：这些瓣膜只能向一个方向开：房室瓣只能朝向心室开，动脉瓣只能朝向动脉开．这样就保证了血液只能按一定的方向流动：血液只能从心房流向心室，从心室流向动脉，而不能倒流．

故选：A

完形填空

根据短文内容及首字母提示，填写所缺单词，使短文意思完整。每空限一词。

Autumn is a season of both harvest and planting. Similarly, when we step into college, we harvest the hard work from high school, and at the same time, we plant hope for our f 小题1:.

Farmers take care of the plants and irrigate(灌溉) them with much e 小题2:. We college students should also make full use of our time and work hard so t__小题3:___we can have a good harvest when we graduate.

Yangzhou University is a good place to plant our dreams. A___小题4:__ a student of Yangzhou university, I always feel proud and lucky to have a c__小题5:___ to study here. It is a college w 小题6: long history. People around me always c__小题7:__ for me, encourage me, and give me love.

Every year in autumn, my college w__小题8:__ new students and guides them to realize their dreams. They’ll spend the best time of their lives to look for the v__小题9:___of life here. I believe that Yangzhou University students will make great achievements someday, because our college is like a__小题10:___ and we will harvest what we plant here.
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多项选择题

以下证券投资风险中属于系统性风险的是( )

A．市场风险

B．财务风险

C．利率风险

D．政策风险

E．经营风险
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