题目

During the years of depression(萧条), food and money were very hard to find and people had to trade things with each other. One day I was   1  some potatoes from Mr Miller. I noticed a small poor boy hungrily   __2   a full basket of freshly picked green peas. Then I was _ 3   to see that Mr Miller sold the boy a bag of peas for just a marble (弹球). Mrs Miller, who had been standing nearby,   4__ and told me that Mr Miller loved to trade with the three boys in the village for peas, tomatoes, and other things  _5   he didn’t really need any marbles. I left the stand, smili若直线l：ax－y+b=0经过直线l1：2x－2y－3=0与直线l2：3x－5y+1=0的交点，求a、b的关系式。