1.一朝被蛇咬，十年怕草绳

Once bitten, twice shy.

2.一言既出，驷马难追

A word spoken is past recalling.

3.一见钟情

To fall in love at first sight.

4.一箭双雕/一举两得

Kill two birds with one stone.

5.一寸光阴一寸金

Time is money.

6.一失足成千古恨

The error committed on impulse may turn out to be the sorrow of a whole life.

7.一将功名万古枯

What millions died that Caesar might be great.

8.一年之计在于春，一日之计在于晨

Plan your year in spring and your day at dawn.

9.一人难称百人意

You cannot please everyone.

10.一气呵成

Never make two bites of a cherry.

11.九死一生

To have a hair-breadth escape.

12.九牛一毛

A drop in the bucket.

13.人生如梦

Life is but a dream.

14.人生自古谁无死

Death comes to all men.

15.人不可貌相

Appearances are often deceptive./Never judge a book by its cover.

16.人山人海

A sea of faces：How many people are there in the stadium? Believe it or not, a sea of faces.

17.人云亦云

Echo others’ words.

18.人面兽心

A wolf in sheep’s clothing.

19.人言可畏

Opinion rules the world.

20.十年风水轮流转

Every dog has its day.

21.十全十美

Leave nothing to be desired.

22.十拿九稳

Win something in the bag.