"……，so it was easier for the detective to watch her."中为什么easy用比较级？

原句是：One monday,there were fewer people in the shop than usual when the woman came in, so it was easier for the detective to watch her.

这里的easier是比较级吧，为什么要用比较级呢，没看到和谁作比较啊。

下面是完整的文章：
People are not so honest as they once were.The temptation to steal is greater than ever before----especially in large shops.A detective recently watched a well-dressed woman who always went into a large store on Monday mornings.One Monday, there were fewer people in the shop than usual when the woman came in , so it was easier for the detective to watch her.The woman first bought a few small articles.After a little time, she chose one of the most expensive dresses in the shop and handed it to an assistant who wrapped it up for her as quickly as possible.Then the woman simply took the parcel and walked out of the shop without paying. When she was arrested, the detecitve found out that the shop assistant was her daughter.The girl `gave`her mother a free dress once a week.

it was so exciting watching him do it. 翻译 "This man was so puzzled It was so noisy at night ( )I could hardly sleep. I was only joking.Why take it so seriously? It was too late.So she hurried____to work 翻译so it was silly of me to say yes. 打听一首 英文音乐 的名字 歌词里有"so beautiful so beautiful It's true……" It was a wonder that ___little food saved___many lives during the war.a)such,so b)so ,so It was so large a room that a hundred people looked lost in it. Beautiful though the nicklace was, we thought it was over-priced, so we did'nt buy it.