Automatic direction finding (ADF) is an airborne _______ the ground direction finding system.
A.part of
B.facility to
C.counterpart of
D.aid to
正确答案是C
Automatic direction finding (ADF) is an airborne _______ the ground direction finding system.
A.part of
B.facility to
C.counterpart of
D.aid to
正确答案是C