What do you read when you are travelling by train or bus? What are other people reading? Perhaps a woman sitting near you is reading a love story. A man is reading a serious biography(自传) about a president. And there's a student reading an English textbook.

    What do their choices(选择) say about them? Do you think you can know them by what they are reading? I have got to tell you that your feelings of them may be quite wrong. The woman reading the love story could be a lawyer. She just wants a light read to take her mind off work. The man reading the biography wants you to think that he is very clever. The student reading the textbook isn't a student at all. She's an English teacher.

    Publishers(出版商) know that some people care what they read on trains or buses and so they put out different types of covers. For example， books about Harry Potter have a cartoon cover for young readers and then another more serious cover for grown—ups.

    So next time you are on a train， look around and see what other people are reading， but don't jump to any conclusions(结论). You will be wrong maybe.

Here is a sentence that you could say， “Don't judge（判断） a book by its cover”.

    How do I know if my older computer is worth repairing? There are several things to consider.

    How old is your computer?

    ____So if your computer is older than that, then it may not have suitable hardware to make repairing worthwhile.

    How much are new computers nowadays?

    Now brand name Windows 9 or Windows 10 desktop computers with 8GB Ram, 1TB harddrive and DVD are $500 or less.____You can find new computers for less, but they may not have a satisfying lifespan of 3-5 years or more.

    ____If you have a computer that you find it hard to get replacement parts, the costs can be high. With that being said, replacing a power supply, video board, cooling fan, or Ram memory chip can be fixed at a fair price____．

    How long will the repair take?

    You should also consider the time! If the computer is used in your business, the cost downtime(停工期)may be a bigger factor than repair cost.____Many big computer stores have to send your laptop out for repair which can take 2-3 weeks. For business or home, one consideration might be to buy a new computer and repair the old computer if possible.

A. Where can I buy a new computer?

B. Many business replace computer every 3-5years.

C. Desktop computer repairs will usually be faster laptop repairs.

D. How much is the repair cost?

E. New brand name laptops with the same features(特征)are $600 or less.

F. Is my old broken computer worth repairing or fixing?

G. If you are a do-it-yourself enthusiast, you can cut the cost of labor!

已知8gA能与32gB恰好完全反应，生成22gC和一定量D，现将16gA与70gB的混合物充分反应后，生成2molD和一定量C，则D的摩尔质量为　 ____