don"t claim to know what you don"t know.

　　不要不懂裝懂。

　　don"t have too many irons in the fire.

　　不要攬事過多。

　　don"t make a mountain out of a molehill.

　　不要小題大做。

　　don"t put off till tomorrow what should be done today.

　　今日事，今日畢。

　　don"t put the cart before the horse.

　　不要本末倒置。

　　don"t trouble trouble until trouble troubles you.

　　不要自找麻煩。

. An idle youth,a needy age. 少壯不努力,老大徒傷悲。

1. Time flies. 時光易逝。

2. Time is money. 一寸光陰一寸金。

3. Time and tide wait for no man. 歲月無情;歲月易逝;歲月不待人。

4. Time tries all. 時間檢驗一切。

5. Time tries truth. 時間檢驗真理。

6. Time past cannot be called back again. 光陰一去不復返。

7. All time is no time when it is past. 光陰一去不復返。

8. No one can call back yesterday;Yesterday will not be called again. 昨日不復來。

9. Tomorrow comes never.切莫依賴明天。