—John has hurt his leg.—Really?? A. Who did that B. Why was he so careless C. What’s wrong

问题补充：

—John has hurt his leg.

—Really??

A. Who did that

B. Why was he so careless

C. What’s wrong with him

D. How did that happen

答案：

A. Who did that

B. Why was he so careless

C. What’s wrong with him

(答案→)D. How did that happen

解析：根据句子意思可知答案为D