Do as the Romans do
入乡随俗。
Do as you would be done by.
己所不欲，勿施于人。
Doing is better than saying.
与其挂在嘴上，不如落实在行动上。
Do it now.
机不可失，时不再来。
Do nothing by halves.
凡事不可半途而废。
Don't put off till tomorrow what should be done today.
今日事，今日毕。
Easier said than done.
说得容易，做得难。
Easy come, easy go.
来也匆匆，去也匆匆。
Every dog has his day.
谁都有得意的时候。
.