The traditional view is we sleep because our brain is “programmed” to make us do so.A. w

问题补充：

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：

A. when

B. why

C. whether

(答案→)D. that

解析：表语从句连接词的选用。that引导表语从句，用来说明主语的内容。根据句意，空格内要填that，说明主语The traditional view的内容。