Do you know _____the Beijing Zoo A.when did they visit B.when will they visit C.when they visited D.when they will visit
问题描述：
Do you know _____the Beijing Zoo
A.when did they visit B.when will they visit C.when they visited D.when they will visit
答
when they will visit the Beijing Zoo是由when引导的宾语从句,做动词know的宾语.
宾语从句中除连接词when提前之外,其他都要符合陈述句语序.