这位拳击手是位近战高手，喜欢在近距离发起猛攻。

The boxer is a skilled ___in-fighter who prefers to launch fierce attacks at close range.

那位高管在公司内部以擅长权术斗争而闻名，是个不折不扣的内斗高手。

The executive was known as a skilled ___infighter who always came out on top in corporate power struggles.