胸导联中最深的S波常出现在（） A．逆钟向转位 B．顺钟向转位 C．V1导联 D．V

臭氧（O₃）能吸收大部分紫外线，保护地球生物．臭氧属于（　　）

A．纯净物

B．化合物

C．氧气

D．稀有气体

IA码是系统内的一种地址代码，以下系统板件没有IA代码的是（）

A、席位处理器板

B、无线电接口板

C、磁石电话接口板

D、PBX电话接口板

以下叙述中错误的是

A．一个工程中只能有一个Sub Main过程

B．窗体的Show方法的作用是将指定窗体装入内存并显示该窗体

C．窗体的Hide方法和Unload方法的作用完全相同

D．若工程文件中有多个窗体，可以根据需要指定一个窗体为启动窗体

The following questions present a sentence, part of which or all of which is underlined. Beneath the sentence, you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.

These questions test correctness and effectiveness of expression. In choosing your answer, follow the requirements of standard written English; that is, pay attention to grammar, choice of words, and sentence construction. Choose the answer that produces the most effective sentence; this answer should be clear and exact, without awkwardness, ambiguity, redundancy, or grammatical error.

The explorers’ chances of surviving the winter, which were good at the beginning of the expedition, dropped as their food supplies dwindled, but not dramatically enough that anyone advocated cannibalism.（）

A. dwindled, but not dramatically enough that anyone advocated

B. have dwindled, but not dramatically enough for anyone to advocate

C. dwindled, but not so dramatically as for anyone to advocate

D. has dwindled, but not dramatically enough that anyone advocated

E. dwindling, but not so dramatically that anyone advocated

下列关于关机顺序的叙述，正确的有（）

A、关机与开机顺序相反

B、先关闭所有的应用程序

C、再关闭主机电源

D、最后关闭外部设备电源