请简述光时域反射计的作用。
参考答案:
光时域反射计又称光纤分析仪,可用来测量光纤断点的位置,测试光纤链路的全程损耗,了解光纤长度分布损耗,.测量接头损耗。
The man is teaching in our school, but,believe it or not,he __ as a business man for 8 years.
A.worked
B.was working
C.had worked
D.has been working
关于绝经期的调护,下列哪项不重要:
A.多宣传,多关怀
B.勤清洁,讲卫生
C.适劳逸,当运动
D.慎起居,适寒温
E.调情志,节饮食