下列各句中，加点的成语或熟语使用恰当的一项是（） A．在整治社区卫生环境时，我们

请问谁是“第一个在脚尖上翩翩起舞的芭蕾明星”？

(B)

Directions: Translate the following passage into Chinese.
Water problems in the future will become more intense and more complex. Our increasing population will tremendously increase urban wastes, primarily sewage. On the other hand, increasing demands for water will decrease substantially the amount of water available for diluting wastes. Rapidly expanding industries which involve more and more complex chemical processes will produce larger volumes of liquid wastes, and many of these will contain chemicals which are noxious. To feed our rapidly expanding population, agriculture will have to be intensified. This will involve ever-increasing quantities of agricultural chemicals. From this, it is apparent that drastic steps must he taken immediately to develop corrective measures for the pollution problem.

结构化程序设计的3种基本结构分别是顺序、选择和______。

机械登记卡片"运转工时"栏应（）统计并填写一次。

A.每月

B.每季

C.每半年

D.每年

在诊断风湿热中，你认为下列哪项不正确（）

A.抗链O不是诊断风湿热的惟一指征

B.红细胞沉降率（血沉）升高及CRP阳性在其他风湿性疼病中也可见到

C.有两项主要表现就可诊断为风湿热

D.风湿热是青少年易患的疾病，超过发病年龄，发病率则明显下降

E.目前由于医疗条件的改善，风湿性心脏瓣膜病已较少见到