现代大型、高速飞机的飞行操纵系统为了减轻杆力（脚蹬力），广泛的采用了有助力的操纵系统，它们是利用（）。

Which word does not go with all the others?

Which word does not go with all the others?

The five major component parts of an airplane are （ ） ．

The airport runway marking is colored （ ）, taxiway and aircraft parking marking is colored （ ）.

A runway used for non-precision instrument approach is usually marked by （ ） ．

A basic VFR runway is marked by （ ） ．

A displaced threshold is marked by （ ） ．

The feature of tri-color VASI is （ ） ．

When on the proper glide path of a 2-bar VASI, the pilot will see the near bar as （ ） and the far bar as （ ） ．

3-BAR VASIS, according to the installation position, is divided into three cross bars: （ ）.