difficulty problem trouble区别

difficulty problem trouble区别 problem.question,trouble,difficulty的区别? difficulty,trouble,problem,quesfior的区别 difficulty,problem,trouble,question的区别 matter.trouble.problem.difficulty可数,不可数 problem trouble的区别 trouble problem区别 difficulty trouble challenge problem意义和用法上的区别,我在完形填空上不会做啊! problem和trouble的区别 question problem trouble wrong 区别 trouble与problem的区别? big trouble和 big problem的区别