I think ____ necessary for a student to master a foreign language.A.this B.that C.its D.it正确答案是D.为什么?这样念起来很不通的感觉,我怎么觉得应该是it's?

英语翻译I think ____ ____ of him ____ you do. 英语翻译I think we still need ____ ____ ____. I think I need ____ ____ more active . I think ____(cook) is for moms. I think music is ____(interesting). I think your bike requires ____(fix) i don't think she is beautiful,____ ____? I'dlike ____ ____ you Chinese,and I think you can hlep me ____ my English. I think he isn‘t an actor.重写句子 I ____ ____ he ____ an actor. I think he is busy today(同义句转换）I think he ____ ____ ____ today. I think I have time this Sunday同义句I think I____ ____ this Sunday 句型转换 .I think Sally is _outgoing_.划线部分(outgoing)提问 ____ do you think Sally ____ ____ 句型转换 .I think Sally is _outgoing_.划线部分(outgoing)提问____ do you think Sally ____ ____ It doesn't help ,I think.（合成宾语从句）I ___ think it___ ____. I think jackie is a good English teacher.(改同义句)I think Jackie ___English ____. I think the book is very good.____ ____ ____,the book is very good 我觉得英语越来越有趣:I think English is becoming____ ____ ____ ____ I don't think he is at home ____ ____ ____(现在)-.- the or this?