First come, first served.
先来后到。
First impressions are half the battle.
初次见面,印象最深。
battle
英 ['bætl] 美 [ˈbætl]
vt.& vi.与…作战; 争斗
n.战争,战役; 比赛,较量; 长期论战或长期作战; 激烈的竞争
First think and then speak.
先想后说。