语法问题,请高手解答..急~

It is good manners for an Arab to stand close to his friend when they are talking.对阿拉伯人来说,交谈时站得离朋友近些是好的礼貌.(主语是??)

It 指代：to stand close to his friend when they are talking

It's very kind of you to think so much of us.谢谢你替我们考虑得这么多.(主语是??)

It 指代：to think so much of us.

Once you start to smoke, you cannot easily give it up.一旦你抽上了烟,你就不容易戒掉.(宾语是???)

It 指代：smoke;此句前半句为状语从句；

The teacher will teach us how to learn English well.老师会教我们如何才能学好英语.(宾语是???)

us 是宾语，后面是宾语补足语

The important thing in life is to have a great aim, and the determination to attain it.人生重要的事是有一个伟大的目标,以及实现它的决心.(表语是???)

表语： important

He was very busy and had no time to visit his friends.他很忙,根本没有时间看望朋友们.(定语是???)

his

In order not to be late,we took a taxi instead of a bus.为了不迟到,我们没有乘公车,而是打的.(状语是???)

In order not to be late

入门级题，拒答。