A：My advice would be to finish it at once.
      我的建议是立刻做完。

B：It’s unnecessary.
      B：没必要。

B：How much (did you pay/ did it cost/ was it)?
      （你花了/付了/它是）多少钱？

A：$14,000.
      1万4千。

B：Yes, it seems to be (working fine/ operating/ functioning properly).
      是的，好像（有用了/可以运行了/可以正常使用了）。

A：Great.
      太好了。

1. 它(指物体、动物或上文已提及的其他事物)
    You use it to refer to an object, animal, or other thing that has already been mentioned.

    e.g. He saw the grey Land-Rover down the bypass. It was more than a hundred yards from him...
           他看见那辆灰色的路虎越野车停在不远处的边道上,离他一百码开外。
    e.g. It's a wonderful city, really. I'll show it to you if you want...
           这真是一座很棒的城市,如果你愿意的话我领你看看。

2. (指小孩或婴儿)它
    You use it to refer to a child or baby whose sex you do not know or whose sex is not relevant to what you are saying.

    e.g. She could, if she wanted, compel him, through a court of law, to support the child after it was born...
           如果她愿意,她可以通过法庭强制他在孩子出生以后抚养孩子。
    e.g. He threw the baby high in the air and it stopped crying.
           他把孩子向空中高高抛起,孩子就停止了哭闹。

3. (笼统指代刚描述过的情景)
    You use it to refer in a general way to a situation that you have just described.

    e.g. He was through with sports, not because he had to be but because he wanted it that way...
           他放弃了体育运动,不是因为被迫而是出于自愿。
    e.g. Antonia will not be jealous, or if she is, she will not show it.
           安东尼娅不会嫉妒,即便嫉妒,她也不会表现出来。

4. (用于某些名词、形容词、动词前说明对某情况的感受、观点)
    You use it before certain nouns, adjectives, and verbs to introduce your feelings or point of view about a situation.

    e.g. It was nice to see Steve again...
           再次见到史蒂夫真是太好了。
    e.g. It's a pity you never got married, Sarah...
           萨拉,你没结过婚真是遗憾啊。

5. (用于被动句中引出一个情况或事件)
    You use it in passive clauses which report a situation or event.

    e.g. It has been said that stress causes cancer...
           据说压力会引发癌症。
    e.g. Yesterday it was reported that a number of people had been arrested in the capital...
           昨天据报道有很多人在首都被捕。

6. (与动词连用,作形式主语或宾语)
    You use it with some verbs that need a subject or object, although there is no noun that it refers to.

    e.g. Of course, as it turned out, three-fourths of the people in the group were psychiatrists...
           当然,结果是那群人中 3/4 是精神病学家。
    e.g. I like it here...
           我喜欢这里。

7. (用作 be动词的主语,指钟点、星期、日期)
    You use it as the subject of 'be', to say what the time, day, or date is.

    e.g. It's three o'clock in the morning...
           现在是凌晨 3 点整。
    e.g. It was a Monday, so she was at home...
           那天是星期一,因此她在家里。

8. (用作系动词的主语，描述天气、光线或温度)
    You use it as the subject of a link verb to describe the weather, the light, or the temperature.

it的近义词

    e.g. It was very wet and windy the day I drove over the hill to Milland...
           那天风雨交加,我开车翻过小山去米兰德。
    e.g. It's getting dark. Let's go inside...
           天色暗下来了,我们进去吧。

9. (尤用于刚接通电话时询问、告知身份)
    You use it when you are telling someone who you are, or asking them who they are, especially at the beginning of a phone call. You also use it in statements and questions about the identity of other people.

    e.g. 'Who is it?' he called. — 'It's your neighbor.'...
           “是谁啊?”他问道。——“是你的邻居。”
    e.g. Hello Freddy, it's only me, Maxine.
           你好,弗蕾迪！是我,玛克辛。

10. (与动词 be 连用，强调突出某物)
      When you are emphasizing or drawing attention to something, you can put that thing immediately after it and a form of the verb 'be'.

      e.g. It's really the poor countries that don't have an economic base that have the worst environmental records...
             确实是那些没有经济基础的穷国的环境记录最差。
      e.g. It was the country's rulers who devised this system...
             是该国的执政者创造了这一体制。

11. 并不是因为/不仅仅因为
      You use it in expressions such as it's not that or it's not simply that when you are giving a reason for something and are suggesting that there are several other reasons.

it

      e.g. It's not that I didn't want to be with my family...
             并不是我不想和家人在一起。
      e.g. It's not just that a gulf exists in living standards — there's a psychological ravine.
             不仅仅是生活水平上存在巨大差异，心理上也有鸿沟。

12. 自以为很了不起
      If you say that someone thinks they're it, you mean that they think they are better or more important than they really are.

13. if it wasn't for -> see See be