“用微观的眼光看世界”是我们学习化学的重要思想方法．试根据以下材料，结合你所学过的知识，简要回答问题：

材料一：一滴水里大约有15万亿亿个水分子，如果10亿人来数一滴水里水分子，每人每分钟数100个，日夜不停，需要数3万年才能数完．

材料二：大多数物质都有热胀冷缩的现象．

材料三：湿衣服在夏天比冬天容易干．

（1）材料一说明：____；

（2）材料二说明：____ ；

（3）材料三说明：____ ．

唐朝的长安城有非常严格的布局，其中繁华的商业区在（　　）

先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中选择可以填入空白处的最佳答案．

    One night I saw something on the news that made me sad．It was1a group of homeless(无家可归的)people sleeping outside in the cold．

    So I decided to start a2to raise many for the homeless．I called it the Rock Club,At the beginning,there were only five members in it，3that quickly grew to about twenty．I didn't have to ask anyone if they wanted to be a4．In fact，they came up to me and asked me if they could5the club!

    We spent all of our free time on rock painting．We painted animals,flowers and even the names of sports teams on our rocks．We'd go around the school to6people who would buy them．By Christmas，we had raised thirty．three dollars and then we gave the money to a homeless shelter(收容所)in town．We all felt7that we could do something to help the homeless．

    A few days later,a newspaper reporter(记者)came to our school to8with us about our club and took a photo of us．The photo and article(文章) 9in the newspaper the next day．Later,10school,joined by three other schools，started a project for kids to help homeless shelters．

    Something as simple(简单的)as some painted rocks and a few caring kids made me know that I don't need much to make a difference．

解释句中划线词语。

①请广于君

②非若是也

③秦王色挠

④寡人谕矣