听力原文：

The Internet consists of a countless number of computers from all over the world that talk to each other. To use it, all you need is a computer and a telephone line. The Internet is good for many things. You can shop on the Internet, look for information and send mail. When you send mail on the Internet, it’s called an e-mail. To use an e-mail, you need to get an e-mail address. This is easy and cheap. Using e-mail is very quick. It can take days or weeks for a paper letter to arrive somewhere, but an e-mail will arrive in a few minutes. With e-mail, you can also send copies of your letter to as many people as you want. Now, you can even send pictures, sounds and short films using your e-mail. But there are still some things that you can’t do with e-mail. For example, you can’t send real things.  

Question: What can’t be sent with e-mail?

参考答案： 

Real things.