At the end of the race his legs and he fell down on the ground.A. gave outB. gave offC. w

问题补充：

At the end of the race his legs and he fell down on the ground.

A. gave out

B. gave off

C. worn out

D. used up

答案：

(答案→)A. gave out

B. gave off

C. worn out

D. used up

解析：考查动词短语：A. gave out用尽，耗尽，精疲力竭（不及物动词短语）B. gave off散发， C. worn out用尽，（这是过去分词的形式，不能做谓语）D. used up用完（及物动词短语），句意：在比赛结束的时候，他的腿精疲力竭，倒在地上。选A。