问题
单项选择题
The writer makes it obvious that______
A．sleepwalkers are often awakened by dangers
B．the underlying cause of sleepwalking is more serious than sleepwalking itself
C．most sleepwalkers are deranged or insane
D．All of the abov
答案
参考答案：B
解析：文章中作者明确指出，引起梦游的原因远比梦游本身严重。