空气中细菌污染的指标，是测定lm3空气中（）的数量
A.沙门菌
B.细菌总数
C.棒状杆菌
D.结核分枝杆菌
E.链球菌
参考答案：B, E
—Where are Tom and Mary?
--____ Tom _____ Mary is busy with their homework. You’d better play with.
A．Both, and
B．Neither, nor
C．Either, or
D．Not only, but also
祖国大陆第一个试管婴儿在哪里出生？
