"咽喉干燥者，不可发汗"病机是（）

A.阳虚浮越于上

B.胃热上炎

C.肝胆火旺

D.阴虚津液不足

E.以上都不是

We are going for a picnic tomorrow. I'll call Wendy to make sure ________. [ ]

A. why to start

B. when to start

C. what to start

D. which to start