— What are you doing outside the class? Didn’t you hear the clock ?
—Sorry, sir. I .
A. strike; didn’t notice
B. striking; wasn’t noticing
C. is striking; didn’t notice
D. struck; wasn’t notice
网友回答
A. strike; didn’t notice
(答案→)B. striking; wasn’t noticing
C. is striking; didn’t notice
D. struck; wasn’t notice
解析：hear sb. doing强调“听到某人正做某事”。第二个空，表示我过去没有注意，表示过去某一时间正在进行的动作，用过去进行时。