下列导航设备中，属于着陆系统的是（）。

“Belly landing “means （ ） .

“Engine partially disintegrated” means the engine （ ） .

The maximum width of an air route is 20km and the minimum width is （ ） km.

The main purpose for extending the flaps is to （ ）.

（ ） carpet may be required for emergency landing.

（ ） is responsible for the use and management of SSR codes.

“Wind shear” is a kind of （ ） .

Automatic direction finding (ADF) is an airborne （ ） the ground direction finding system.

ADS is a means for（ ）.

Before providing radar service, air traffic controller should（ ）to the aircraft.