口服不吸收，临床主要用于绿脓杆菌感染治疗（）
A．青霉素V
B．苯唑西林
C．替卡西林
D．哌拉西林
E．舒巴坦
参考答案：C
It is difficult to ____ one twin from the other. They almost don’t ____ from each other.
A．differ, distinguish
B．distinguish, differ
C．distinguish, different
D．tell, different
可以将流程概括为先听后发、边听边发、冲突停止、随机延迟后重发的共享介质局域网是( )。
A．CDMA/CD
B．TDMA/CD
C．CSMA/CD
D．FDMA/CD
