判断细菌性食物中毒除定性检验外，必须做()
A．药敏试验
B．活菌计数
C．耐药试验
D．动力试验
E．动物试验
参考答案：B
The old man could cross the busy street _____ the help of his dog. [ ]
A. under
B. behind
C. with
D. for
卡拉玛佐夫气质
