民航航空器及交由民航保障的其它部门的航空器的飞行，其管制工作是在（）的原则下，由（）实施管制服务。

The most significant limitation of VHF signals is that they （ ） ．

Aircraft with a flight range greater than （ ） km are long-range aircraft.

When transmitting time, 09:16 can be given as （ ） ．

When flying from northeast to southwest on stable warm front, the A/C will pass cloud in the sequence of （ ） .

In radio communication, 1:30 p.m. is transmitted as（ ）．

When transmitting time, 6:18 p.m. is given as （ ） ．

In radiotelephony, FL390 is transmitted as （ ） ．

In radiotelephony, the altitude 18,500 is transmitted as （ ） ．

In radiotelephony, the altitude 8,500 is transmitted as （ ） ．

Constant attention to correct phraseology and procedures will （ ） ．