转子流量计是以压降不变,利用()的变化来反映流量大小。
A、节流体积
B、节流面积
C、节流压力
D、节流介质
参考答案:B
按照所具备的技术等级可以把导游人员划分为()
A.初级导游
B.中级导游
C.高级导游
D.特级导游
When it is advisable to remain on VHF channel 14 you should say().
A.stand by on VHF channel 14
B.come to VHF channel 14
C.VHF channel 14 is the best place for you to stay by
D.remain in channel 14 and do not change