第1个回答 2007-01-20
Are these books theirs?
第2个回答 2007-01-20
Do these books belong to them?
第3个回答 2007-01-20
Are these books theirs?
Are these their books?
都可以
第4个回答 2007-01-20
Are these books their?
第5个回答 2007-01-20
Are these books theirs?
Do these books belong to them?