It is 2018; e-books are loved by many people. Do you read them?

An e-book is an electronic book, which can be made from common books and loaded onto an e-reader. The e-reader is a mini-device, just like a cell-phone. It has a touch pad screen and can hold a few hundred e-books. People can read e-books on it just like they do a book. So it is possible for people to read anywhere with an e-reader. This is perfect news for people who love to read books but can’t carry many.

Another great thing is that people can read books on it quickly and there’s no need for two hands to hold the book and turn pages. Most e-readers also have a nightlight, so you can read at night and don’t wake your partner with a big light on.

Not all book authors agree to make their books into e-books. The creator of Harry Potter says that her books will never be e-books. However, lots of authors absolutely love the idea and feel it’s the next step to keep books alive.

Nowadays e-books are sold in many websites, from where you can buy and load them onto your e-reader. Those websites look just like ordinary online bookstores and have a list of best sellers and a new book section. There is also a clear price on each e-book to make sure people can buy them like buying common books.

Database maintenance (数据库维护) is an activity designed to keep a database running smoothly. A number of different systems can be used to build and maintain databases. Databases are used to maintain a library of information in a well-organized, accessible format (格 式).They usually are not static (静态的),because changes are constantly being made as material is added, removed, and moved around. Over time, this can cause the database to start to go wrong. Database maintenance is used to keep the database clean and well-organized so that it will not lose functionality.

One important aspect of maintaining a database is simply backing up the data so that, if anything happens, there will be another copy available. Some database systems actually do this automatically and then send the backup to another location every day, every week, or within any other set period of time. Backups are usually not enough, however.

Database maintenance includes checking for signs of corruption in the database, looking for problem areas, and checking for any detail in the database that might signal a problem. The goal is to keep the database operating smoothly for users, so that ideally they never need to think about maintenance issues. A database that is not maintained can become slow, and people may start to experience problems when trying to access records.

The maintenance of databases is generally performed by people who are comfortable and familiar with the database system and the details of the particular database, although some maintenance tasks can be performed by people who do not have experience. Numerous textbooks are available with information about database management, including how to maintain databases properly. It is also possible to take courses to learn about different database systems and how to care for databases. People can also earn certifications in specific systems which indicate a high level of competence.

With the help of the Internet, shopping is not a difficult thing. Just click your mouse, and you can choose the article (物品) you like, and the shopping is finished. You needn’t walk out of the room. It seems easy and quick. But there are always traps (陷阱) on the Internet. If you are careless, it will bring you some trouble. You may find the colour of the article is different from what you want, or the size is either too small or too big. If you want to be different, you’d better not buy clothes on the Internet. Once you put on the clothes you buy on the Internet and go out, you will find many people wear the same clothes in the street.