在下列导航设备中，既可用于航路，又可用于终端区的是（）。

“Indicated speed” is （ ） .

Radar works on an （ ） principle.

“Radar” means Radio Detection and （ ） .

Flight information centers shall provide flight information service and （ ） service within the regions.

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 （ ） .