问题
选择题
He must have gone out. I heard the noise of the door ______when I was still in bed.
A．being locked
B．to lock
C．locking
D．having locked
答案
答案：A
考查非谓语动词和固定用法。句意“他一定是出去了。当我没起床时，我就听见了锁门声。”door和lock之间是被动关系，应该用被动语态。hear sb./sth. doing sth.“听到正在做某事”。故选A。