下列业务中，不属于移动通信的是（）。
A.无线寻呼业务
B.蜂窝电话业务
C.集群调度电话业务
D.光纤接入
参考答案：D
原发性肺结核的发生最重要的因素是因为（）
A.感染的细菌数量大
B.机体对结核菌处于过敏状态
C.细菌毒力较强
D.机体对结核菌缺乏免疫力
E.患者年龄较小
Which of the following statements is most accurate A method of production is economic efficiency when:（）
A. It uses the most advanced science and technology.
B. The cost of fund capital is as low as possibie.
C. The cost of producing a given level of output is as low as possible.
