问题
选择题
— I phoned you yesterday morning. A girl answered, but I didn’t recognize the voice.
— Oh, it ____ my younger sister. She was in my room at that moment.
A．must have been
B．should have been
C．could have been
D．may have been
答案
A
题目分析：句意：—我昨天早上打电话给你。一个女孩接的，但我没听出是谁的声音。—哦，一定是我的小妹妹。她那会正在我的房间。A. 一定是，肯定推测；B. 本应该；C. 可能是；D. 也许是。结合语境，选A。
考点: 考查情态动词表推测的用法。