题目

I needed to get some money so, after Christmas, I took a job in the clothes department at Graham’s for the first fortnight of the January sale. I can’t say that I enjoyed it, but it was an experience I’ll never forget. I could never understand why there were so many things in the sales; where did they all come from? Now I know the secret! Firstly, there is the special winter stock (货物) and the stock that people buy all the year round; some of these things are slightly reduced. Secondly, there are the summer clothes they couldn’t sell last year; these are heavily reduced to clear th10．达瓦同学站在竖直放置的平面镜前1m处，他的像距平面镜1m．当他远离平面镜0.5m时，他的像距平面镜1.5m，他在平面镜中的像的大小不变（选填“变大”“变小”或“不变”）．