超短波的波长范围是
A.300~3000m
B.100~1000m
C.100~300m
D.10~100m
E.1~10m
参考答案:E
解析:1~10m是超短波的波长范围。
Hurry up ___ we ___ miss the train.
A.and, are about to
B.or, are about to
C.or, will
D.and, shall
直通阀、角形阀、三通阀等是根据()划分的
A.流体的流通性
B.阀的传动机构
C.阀的耐温情况
D.信号的作用