在远动装置接收信道上收到信号电压为0.4伏，此值相当于（）dBm。
A.0.4
B.-0.4
C.5.74
D.-5.74
参考答案：D
填空，补全对话。
A: May I go on a trip to Shenzhen, Mum?
B: To __________? I don't know, Jenny.
A: It's a famous city.
B: Is it very far __________ Shijiazhuang?
A: Yes, very __________.
B: I think you're __________ young __________ go there, Jenny.
对流场干扰最小的测流速仪器是哪种仪器?
A.毕托管
B.旋桨式流速仪
C.激光测速仪
D.浮标测速
