已知铝原子的结构示意图为 ，则铝原子核内有____个质子，原子核外有____个电子层。

下面词语中没有错别字的一项是（   ）

21世纪的新兴领域纳米技术正日益受到各国科学家的关注，2000年美国总统宣布了纳米倡议，并将2001年财政年度增加科技支出26亿美元，其中5亿给纳米技术．纳米是长度单位，1纳米等于____ 米，纳米科学与纳米技术是研究结构尺寸在l～100nm范同内材料的性质与应用．它与胶体分散系的粒子大小一样，检验这种分散系常用的方法是____ 

阅读下面短文, 按照句子结构的语法性和上下文连贯的要求, 在空格处填入一个适当的词或使用括号中词语的正确形式填空。

    Reading is a good hobby for all kinds of reasons.

    First, reading is fun. You can always keep ____（you） happy if you like reading. You will never ____ (feeling) bored or tired.

    Next, you can read a book anywhere—in ____ car, on a plane, or even in the bathroom. All you need ____ (be) a book!

    Another good reason for reading is that it is ____ (use). If you read ____ a hobby, you will get better and better at it. And you will read faster and find it easier to understand ____ you read. As your reading skills improve, you will ____ (probable) find your schoolwork becomes much better.

    Some people say that reading is out of date. This is not true. You can read on computers, and the better you read, the ____ (good) your computer skills will be.

    Good readers may become ____ (writer), too. They always have more things to write about.