B
句意:既然你不能改变,你所能做的和要做的就是用补丁覆盖在伤口上,尽量在伤口上做出最美丽的花,这就是生活教给我们的。
A.Till直到
B.Since因为,自从,既然
C.Unless除非
D.So因此
根据语境" (14)you can't change that, all you can do and have to do is to cover the wound by patches and try your best to make a most beautiful flower on the wound" (14)你不能改变,你所能做的和要做的就是用补丁覆盖在伤口上,尽量在伤口上做出最美丽的花。可知,前后文是因果关系,因此是"since"引导的原因状语从句。故选B。