90．測距儀 DME 和航管系統 ATC；其間相互關係： (A)地線防止干擾‧By ground wires to prevent interference. (B)抑制線路 (suppersion line)防止干擾‧By suppression cables to prevent interference. (C)開路防止干擾‧By open circuit to prevent interference. (D)電容線路防止干擾‧By capacity circuits to prevent interference.