农民用大蒜的蒜瓣埋在土壤里面长出葱绿的大蒜，这种无性生殖的类型是（ ）
A．营养生殖
B．分裂生殖
C．出芽生殖
D．孢子生殖
答案：A
— What happened to Tom?
— He was crossing the street ____ a motorbike hit him from behind. [ ]
A. while
B. when
C. until
D. because
我国的“三资企业”是指______、______和______。
