pron.

1. （指已提及或心目中的人或事物）这，那，它
   This is our new car. I bought it yesterday.

   这是我们的新车。我昨天买的。

2. （指无生命物、动植物、性别不详的幼孩等）它
   What a beautiful baby -- is it a boy?

   多漂亮的孩子啊，它是男孩吗？

3. （作无人称动词的主语）表示时间、气候、距离等
   It's about 50 kilometers from here to my ranch.

   从这儿到我的牧场约有五十公里。

   It's early yet.

   还早呢。

   It's very hot.

   天真热。

4. （置于句首或句中）引导短语或从句
   I'd think it well worth while to go.

   我觉得很值得一去。

5. （作为形式上的主语或宾语）用于表示强调的句型中
   But here it's my word that counts.

   但这里是我说的话算数。

6. （用于某些动词、介词后面）构成习惯语
   Don't lord it over your friends.

   不要对你的朋友摆威风。

n.[U]

1. （捉迷藏等游戏的）捉人者，猜的人
2. 【口】（仅用于gin and it）意大利苦艾酒
3. 【口】关键，重要时刻
   This is it -- we have to act at once.

   现在是关键时刻了，我们得马上行动。

4. 【口】性感；性交
5. 【美】【俚】笨蛋

pron.

1. used to refer to a thing previously mentioned or easily identified.
   ▸referring to an animal or child of unspecified sex.
2. used to identify a person.
3. used in the normal subject position in statements about time, distance, or weather.
4. used in the normal subject or object position when a more specific subject or object is given later in the sentence.
5. used to emphasize a following part of a sentence.
6. the situation or circumstances.
7. exactly what is needed or desired.
8. informal sexual intercourse or sex appeal.
9. (in children's games) the player who has to catch the others.

n.