坐吊板时,必须辅扎(),并将安全带挂在吊线上。
A.安全带;
B.安全绳;
C.安全扣;
D.安全阀
参考答案:A
— Could you please tell me ______ in today’s newspaper — Sorry,______
A. something special; special nothingB. special something; special nothingC. anything special; something specialD. something special; nothing special
卫星系统下行链路主要设备有:低噪声放大器、接收信号分路器,()、中频放大器、滤波器及解调器等组成。
A.下变频器
B.功放
C.功分器
D.上变频器