They hope the (friendship) between their countries will last long.
2.At last he (realized) that he made a lot of mistakes.
3.Chinese people should not be afraid of any (challenges) outside.any后面跟复数吗？如果是可数名词的话应该用复数那么，请问challenge是可数名词吗？嗯，是可数的我记得any当任何讲的时候，后面应该跟单数呢？否定句和疑问句里是一些的意思，可数名词加复数，不可数则不用。在肯定句中表示“任何”的意思，它后面的可数名词用单数形式，如Any student can answer this question.任何学生都可以回答这个问题。