When several runways are in use and there is any possibility that the pilot may be confused as to which one to use, the _______ should be stated in the takeoff clearance．

单选题

When several runways are in use and there is any possibility that the pilot may be confused as to which one to use, the _______ should be stated in the takeoff clearance．

答案解析

单选题

When assigning runways for takeoffs and landings, air traffic controllers will refer to runways numbered “36L, 36C, 36R” as “_______”.

答案解析

单选题

Only when he had handed in his exam paper _____ he had made several grammatical mistakes.

答案解析

单选题

Large “Xs” painted on runways indicate that _______ ．

答案解析

问答题

when

答案解析