It is important to insist it on.So don't get discouraged or give up.If you stick with it,i promise that one day you'll look back on this and you'll be really glad you decided to hang on.It's one of those things that after you understand it,you'll wonder why you once thought it was so hard.
 
 
做事情重要的是坚持.所以不要轻易泄气和放弃.如果你坚持下去,我保证当有一天你回首时会庆幸你当时做出了坚持的决定.一些事情在你理解之后会奇怪为什么当初觉得它这么难.这就是其中之一.