电波是不能在（）中存在的。

The holding position is usually at the （ ） .

I read the Met report to the pilot but he did not answer so I told him to（ ）.

When executing a flight, the flight crew should check in （ ） before ETD and make well pre-flight preparations.

What are the methods to transfer radar identification?

What is the purpose of Standard Instrument Departures?

When the weather at the landing airport or alternate airport is （ ） , a second alternate airport is to be specified.

To what are silent departure procedure specified in Letters of Agreement between facilities?

GAB （ ） 20 miles east of ZW, continue present heading.

KLM261, radar terminated, （ ） own navigation.

GHP maintain FL090, for （ ） turn left, heading 210.