使用钢轨探伤仪对正线钢轨每()检查1遍。
TD-SCDMA的工作频段为:() ["1880~1920MHz","1920~1960MHz","2010~2025MHz","2300~2400MHz"]
利福平的作用位点是RNA聚合酶的() ["A、α亚基","B、β亚基","C、β‘亚基","D、δ亚基","E、γ亚基"]
HARQ是()技术相结合的纠错方法 ["ARQ","FFT","16QAM","FEC"]
大肠杆菌RNA聚合酶的主要形式由5个亚基组成,其中()起识别启动子的作用 ["A、α亚基","B、β亚基","C、γ亚基","D、δ亚基","E、ε亚基"]
UNIX系统中的优先权和优先数有什么关系?如何确定进程的优先权和优先数?