they saw some athletes run in the gym we think it wrong to s

they saw some athletes run in the gym ----run 改为running.意思是：他们看到一些运动员在健身房里跑步.run的动作是正在进行的.要用ing.

we think it wrong to shout at children who make mistakes.---it 后面加上is. it is 后面还带了一个句型,在这里引导宾语从句做we think的宾语成分.
the desk need repairing---改为repair.情态动词need,意思是“需要”,情态动词后面都要跟动词原形的.这是规定.

前句为：Some athletes were seen to run in the gym.
后句为：We think it is wrong for children who make mistakes to be shouted at.
望采纳 谢谢！