你吃过糖拌西红柿吗？它是一种很受欢迎的中国式凉菜。做工简单，又富有营养。
请根据你的生活经验和所给提示词介绍一下这道凉菜的做法。词数在60~80之间。要求
语法正确，语言流畅，介绍过程层次分明。
     Ingredients: two teaspoons of white sugar,  three tomatoes 
     Key words:  cut,  put…into,  add to,  mix… 
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                       Where does gum (口香糖) come from?
     People like gum. But where does gum come from?
     At first, all gum came from trees. These trees have something inside. It looks like white water, which
can be made into gum.
    Now most gum is made from other things. But some gum still comes from trees.

1. People ______ gum.

A. like
B. drink
C. hate
D. write with

2. This story tells us where gum ______.

A. grows
B. comes from
C. is made
D. is

3. At first, all gum came from ______.

A. animals
B. trees
C. other things
D. water

4. The trees have something inside that looks like ______.

A. something
B. other things
C. gray gum
D. white water

5. Now, all gum comes from trees, doesn't it?

A. Yes,it is.
B. Yes, it does.
C. No, it isn't.
D. No, it doesn't.