I think it hard to learn English well if we don't work hard 中it的用法

I think it important to study hard和l think it is important to study hard哪个句子是对的?为什么? I think it important to study hard和l think it is important to study hard哪个句子是对的?为什么? think it hard to do 和 i think it's hard to do 有什么区别 it hard to think i am sorry to heard them I think it hard to fall asleep in night.请问it后为什么不加is. I think it hard to fall asleep in night.为什么it后面没有is I think it hard to learn English well if we don't work hard 中it的用法 请问如何将'' I think it is hard to learn English well '改为否定句. Is that true that it's hard to be a person?I don't think so! I think it hdrd to learn English.哪个是主语?hard It rained____(every hard)and I began to think of my next day outing. i think [ ] hard to learn english well if we don't work hard.a.it b.that c.this 急 我写了一篇作文,谁帮我看看,找些错误(我才初一啊)I have a dreamWhen l am boy,l want to be an astronaut.I think it is very interesting and funny.but now I am diffident,I think it is too hard.I have not any hope.So I have a new dream: 关于think is,英语语法例句：I think it is hard to say.这是什么结构?为什么两个动词可以连用? I think it--question-- C too hard a;to answer D a too hard; to answerB答案为什么不对，以及为什么是too hard a question 而不是a too hard questionB such a hard; to answer I think it to learn English well if we don'twork hard.的分析I think it to learn English well if we don'twork hard句中it后面该不该填is. it I think is hard donnot 连词成句 you think it is a good habit to study hard