题目

The traditional view is ______ we sleep because our brain is “programmed” to make us do so. A. when B. why C. whether D. that 答案：D 解析: 引导名词性从句的从属连词that与whether的区别是:句子成分完整且表意确定时选用that连接,句意不确定时选用whether/if连接;借助it,将真正主语或宾语后置,构成“It…that”句型,但whether/if不可;下列情形用whether不用if:与or not 连用,中间无其他词隔开;作介词宾语;在主语从句??表语从句和同位语从句中??According to the United Nations, an aging society refers to one ____ 10 percent or more of the population is over 60, or 7 percent or more is over 65.     A. where           B. when             C. which            D. that