使用含铅量大的汽油工作时，电嘴（）最易积铅。

Airport lighting system should be opened twenty minutes before the aircraft is expected to （ ） ．

Large “Xs” on taxiways indicate that （ ） ．

Large “Xs” painted on runways indicate that （ ） ．

The area preceding a displaced threshold cannot be used for （ ） ．

Which statement below is not true?

If a displaced threshold marking is seen on a runway, which of the following is not true?

The （ ） section of the turbofan engine supplies compressed air to the A/C.

Which runway marking may not be seen on a non-precision runway?

Instrument approaches using the vertical guidance to the landing runway are called （ ） ．

When ILS approaches are in progress, the controller may ask the pilot to “hold short of the ILS critical area”. This does not imply that （ ） ．