题目

Someone says,“Time is money.” But I think time is______important than money.Why?Because when money is spent,we can get it back.However,when time is______ it’ll never ______That’s_____we mustn’t waste（浪费） time.It goes without saying that the______is usually limited（有限的）.Even a second is very important.We should make full use of our time to do______ useful.But it is a pity that there are a lot of people who_____ know the importance of time.They spent their limited time smoking,drinking and playing.They do not know that wasting time means wasting part of their own ____（2003•娄底）一个两位数，十位数字为a，个位数字为1，这个两位数用代数式表示    ．