DME共有（）个频道。

Inertial navigation systems are （ ） devices.

The term knots when referring to speed means （ ） per hour.

A compass needle points to the （ ） .

The height of the mercury column will decrease by nearly one inch for each （ ） ascent.

（ ） is a kind of source of power which can provide power to operate many major aircraft systems.

For the aviation aircraft, the fuel tanks are usually mounted in the （ ） .

（ ） is a kind of unlawful interference.

The ground speed of an aircraft is affected by a （ ） which would reduce it, or by a （ ） which would increase it.

The holding position is usually at the （ ） .

Airborne SSR transponder is in fact a （ ） .