1.fleeting show
人世如白驹过隙。
The world is like a fleeting show.
汉英综合大词典白驹过隙 [báijūguòxì]
[成语] a glimpse of a white colt flashing past a chink in a wall (said of the fleeting of time)
2.光阴似箭 Time flies.
或 Time flies like an arrow 光阴似箭
光阴似箭。我们可不能总是玩呀。
Time flies. We can't play all the time.