The pilot,(飞行员) whether or on purpose, made the plane do a sharp turn.(急转弯)
A. by accident
B. at times
C. suddenly
D. at once
网友回答
(答案→)A. by accident
B. at times
C. suddenly
D. at once
解析：考查短语必须。by accident偶然；at times有时；at once立刻。根据句意：是偶然的或有目的的，故选A。