汽轮机的机头是固定在机座上的。
参考答案:错
— What would you do if it ____ tomorrow?
— We have to carry it on, since we've got everything ready.
[ ]
A. rain
B. rains
C. will rain
D. is raining
产后病的病因病机可归纳为哪四个方面?产后病的病机特点是什么?