I think it our duty to study.I think it completeI think it our duty to study.I think it complete a waste of money.为什么第一句是对的,第二句却是错的?

I think it's our duty to keep our environment clean and tidy. I think it our duty to study.I think it completeI think it our duty to study.I think it complete a waste of money.为什么第一句是对的,第二句却是错的? I think it our duty to study.I think it completeI think it our duty to study.I think it complete waste of money.为什么第一句是对的,第二句却是错的呢? I think __our duty to keep our evirionment clean an tidy.A.this B.that C .it D.it's 关于think 的用法有这样一个句式 sb.thinks it +adj.to do但如果是想要表达 I think it is + n.（如 I think it is our duty to ......） 时是否有be动词存在? we think it our duty to help others为什么不加IS啊we think it is our duty to help others we think it our duty to help others为什么用 it 不用 this that We think that it is our duty.（改为强调句） I think it my duty to write to you and thank you.(改为复合句)I think it ____ my duty ____ ____ to you and thank you. I think it my duty to write to you and thank you.(改为复合句)I think that it ____ my duty ____ write to you and thank you. 37.—Don’t you think it our duty to make our country more beautiful?—Yes.And I _____ all of us.A.believe B.decide C.invite D.request we think it our duty to help the people in trouble分析下句子成分 为什么不是It’s I think it’s my duty to live a low-carbon life. I think It's my duty ______ make meals for my childen.不可灌水 I think it my duty to write to you and thank you.翻译 it is our duty to do i feel it our duty to help the poor boy我是想 搞清楚这个句子里的our duty 是什么句子成份。 I think (it) must be our monitor.为什么填it?