确诊肺结核最重要的依据为

A．典型的症状、体征

B．结核菌素实验阳性

C．痰中找到结核菌

D．血沉加速

E．X线发现病灶

—Do you know ______ last night?  

—Sorry , I don't know. But I  think he should go to bed early

because he will have an English exam this afternoon.  [ ]

A. when he goes to bed    

B. when he went to bed    

C. when did he go to bed    

D. when does he go to bed