题目内容：

    For thousands of years, salting was a common way to preserve food. Corned beef (咸牛肉）, bacon, green beans, and hundreds of other foods were preserved with salt.1. Then, in the 1800s, a Frenchman named Louis Pasteur discovered the secret: bacteria.

What does salt have to do with bacteria? Two things: First, bacteria need moisture (水分）to grow and multiply. Salt pulls moisture out of food, so the bacteria die. 2. If you cover food with salt or very salty liquid, bacteria outside the food die before they get in, and bacteria already in the food are poisoned by the salt that goes inside.

3. For meat or fish,you pour on a layer of salt, then rub it in well, leaving a salt crust (盾）all over the outside. Hams are often made this way. Another way is to put food into very salty water, called brine (卤水）.4. The salt will draw the moisture out of the food, creating a kind of brine that the food sits in.

Today, in most parts of the world, salting, is no longer necessary. 5. But even though we no longer rely on salt to keep our food fresh, we haven’t lost our taste for salt. We don’t want to give up our bacon, corned beef or salted beans.

A.So how do you preserve food with salt?

B.Next, it can make food too salty to eat.

C.Second, salt is poisonous to many bacteria.

D.But for a long time, no one knew why salt worked.

E.You can alternate layers of food and salt in a big jar.

F.People buy food in cans, keep it in the refrigerator, or freeze it.

G.They use salt to preserve meat, fish, vegetables, and even fruit.