163．When using a hand held smoke signal from a lifeboat, you should activate the signal __.
举一反三
- （）is the most visible signal of distress from a lifeboat at sea in the daytime.
- 159. If you receive the signal over radiotelephone of Romeo Papa Tango while using the
- 智慧职教: Who transmits and receives signal to and from the satellite using L band frequency?
- When changing lanes, a driver should use his turning signal to let other drivers know _______.
- When changing lanes, a driver should use his turning signal to let other drivers know______.