梯级下降定位点是指（）。

Which of the following is not a correct procedure?

That aircraft fly wrong routes or change routes without authorization is （ ） ．

If, at any time, the pilot is given an instruction that is beyond his airplane＇s capabilities or is not safe to follow, which of the following practices is not right?

When establishing communications, （ ） ．

A radio that combines a transmitter and receiver in one unit is called a （ ） ．

Which statement below is not true?

The identification markings of civil aircraft include （ ） ．

The phrase “go ahead” means “（ ）”．

A radio transmitter is activated when the （ ） ．

In radiotelephony, the call sign for a controller for （ ） is Ground．