选4
they stayed at the hotel ,at the hotel 做的是状语,所以用where,不选1
2中,at与 that不能连用,3中是they,不加at 总之,如果题干中没有at说明缺状语,用where 有的话,缺宾语,用that
改正:
1.which they stayed at
2.at which they stayed
3.where there stayed
4是正确的
which要加at
where不用
where可以相当于at which
答案是4
有where就不用加at, 如果要加at就要用at which 而不是 at that
3