Question

Malaysia Airlines Flight 370 ___________ course and turned back toward Kuala Lumpur -- but there were no indications from the pilot that he was doing so.

A．must have changed	B．could have changed
C．might have changed	D．should have changed.

Answer 1

C

解析试题分析:句意：马航370客机可能已经改变航向，折返吉隆坡——但是没有飞行员这样做的迹象。A肯定做过某事；B本来有可能做（但是没做）；C可能做过；D本应该做（但是没做）。根据破折号后可知这是猜测可能发生过的事情，故答案选C。
考点：考查情态动词用法。