When the plane arrived, some of the detectives were waiting inside the main building others were waiting on the airfield.
A. during
B. where
C. which
D. while
网友回答
A. during
B. where
C. which
(答案→)D. while
解析：while 作并列连词，表示对比或相反的情况，意为“而、却”。句意为“当飞机抵达时,一部分侦探等在主楼里面，而另一部分则等在停机坪上。”