低速暖机时,若真空太高,暖机时间会()
A.缩短
B.不变
C.加长
D.不一定
参考答案:C
This is an unpleasant subject_ ____ we might argue for a long while. [ ]
A. in which
B with them
C. about which
D with it
含濒危野生动植物成分的药品