draw the first blood

• 首先进攻,先下手为强

draw the first blood的用法和样例：

例句

1. The first blow is half the battle.
   先下手为强。
2. Actually one is striking first to gain the advantage when one finds oneself in disfavour a means of self protection in essence.
   当感到对方不喜欢自己时，我们先下手为强。