飞机在着陆时，起落架红色指示灯亮起，则下列说法错误的是:

Unlike DME, both VOR and ADF do not include an airborne （ ） ．

DME and VOR have similar airborne equipment except that DME includes （ ） while VOR does not.

DME measures （ ） ．

DME provides a distance reading in （ ） ．

DME adds to a basic VOR system another feature, namely （ ） ．

Flying from one radial to another is normally referred to as （ ） the radial.

The CDI needle of the VOR indicator shows the pilot that his aircraft is not on course when it （ ） ．

（ ） is not a necessary step to use a VOR effectively for navigation.

（ ） guided approach is non-precision approach.

The VOR signals travel on a line-of-sight basis. This means （ ） ．