—What's your favourite fruit?
—I like . [ ]
A. fish
B. grapes
C. pork
答案:B
滑石粉炒制时,每100kg药物用滑石粉的量是()
A.5kg
B.10~15kg
C.20~25kg
D.30~35kg
E.40~50kg
简述挤管机头的结构形式及各自特点。