问题补充：
-Excuse me. Do you know?
- Last Sunday.
A. where he would like to visit
B. when he was back home
C. how he came here
D. why did he come to the zoo
答案：
A. where he would like to visit
(答案→)B. when he was back home
C. how he came here
D. why did he come to the zoo
解析：句意：--打扰了。你知道他是什么时候回到家的吗？--上个星期日。分析考查宾语从句，宾语从句要用陈述语顺，同时结合答语回答是时间，因此对时间的提问用疑问词when，故选 B
