them

　　B．customers should be careful with their credit cards when shopping online

　　C．customers must give their e­mail addresses as well as their phone numbers

　　D．people can know different opinions of all customers

　　B　[细节理解题。根据第三段最后一句 "...you have to be careful with your credit cards." 可知答案。]

　　4．If you want to buy a cup online, what is the right order of the following things you can do?

　　a．Put the cup into your "shopping cart"．

　　b．Wait for the confirmation of the order.

　　c．Search for a right cup.

　　d．Enter the address.

　　A．b-c-d-a　　 B．c-a-d-b

　　C．a-b-c-d D．c-d-a-b

　　B　[细节理解题。根据最后两段内容可知， 在网上购买一只杯子(cup), 首先要找到合适的产品， 然后把它放入购物车中， 然后登录， 输入收货地址， 最后等候确认。]

　　B

　　It is amazing how many of the things in science fiction and movies have become reality.For instance, in the movie Star Trek, the workers could go to a replicator(复制器) and order food, drinks or anything they could program into the computer.Before long, the item would appear.This is possible today, in a way, with technology we have had for years.

　　Several manufacturers(制造商) have created 3D printers.One company, MakerBot, has created a printer that the average person can afford.It is called The Replicator.You can download a lot of design software from the Internet for use with The Replicator.In the near future，rather than going to a store to buy what you need, you may be able to download what you want from the Internet and print it out at home.

The process was first used with music.At the very beginning, music was recorded