As we know every four years athletes from all over the world compete medals in the Olymp

问题补充：

As we know, every four years athletes from all over the world compete medals in the Olympic Games.

A. against

B. for

C. with

D. as

答案：

A. against

(答案→)B. for

C. with

D. as

解析：考查介词：ABC都可以搭配compete，A. compete against和…竞争B. compete for为了…而竞争，C. compete with和…竞争，句意：我们都知道，每四年来自世界各地的运动员都会在奥运会中为了奖牌而竞争。选B。