未知题型 Social networks websites are used by many employers because the former______.A．help reveal what kind of person an job candidate isB．can spread the information of the company in a fast wayC．save companies lots of money on communicationD．help improve employer-employee relationship

单项选择题 光监测信道(OSC)的光功率是（ ）的测试项目。A. SDH传输设备B. 波分复用传输设备###SXB##

单项选择题 在卫星地球站天线入网验证中，（ ）测试是强制性项目。A. 输出噪声B. 天线发射方向图###SX