假如英语课上老师要求同学们交换修改作文，请你修改你同桌写的一篇作文。文中共有10处语言错误， 要求你在错误的地方增加、删除或修改某个单词。
增加：在缺词处加一个漏字符号（∧），在其下面写上该加的词。
删除：把多余的词用斜线（\）划掉。
修改：在错的词下划一横线，并在该词下面写上修改后的词。
注意：1．每处错误及其修改均仅限一词；
2．只允许修改10处，多者（从11处起）不记分。
Good morning!
Today, my topic is the valuable of time. Time, like the proverb says, is money. This means that if our time is good spent, it will turn out a lot of useful and important piece of work when the proper opportunity come. Although all time is precious, but the time of our youth is more precious than any period of our existence because this is the period which we can acquire knowledge and develop our abilities. If we allow these morning hours to slip away, we shall never able to make up for the loss.
Let those who think nothing of waste time remember this. Thank you for your listening!