I think they are interesting中的they为什么不用宾格?

I think they are interesting中的they为什么不用宾格? 不是及物动词后面要跟宾格吗,think是及物动词.I think they are great.为什么they 不用宾格 they,interesting,do,I,are,think,not I think they are interesting.改为一般疑问句 I like elephants because they are interesting. where are they I think they are at a ()()一空一词 I think they are pretty big i don't think they are right ------ I think they are too sweet. I think they are at home? I think these bikes are ( )(they) they.are.chinese.chinesr为什么不用china