问题补充：
you stepped into the lab with your shoes on? You are supposed to take them off before you enter it.
A. How come
B. How about
C. How dare
D. How long
答案：
(答案→)A. How come
B. How about
C. How dare
D. How long
解析：词义辨析A. How come 为什么 B. How about （用于建议）…怎么样？ C. How dare 怎么胆敢 D. How long 多长“你为什么穿鞋进实验室？你应该在进入前脱掉鞋子”选Ａ
