Chemistry is about the smallest things that other bigger things are made of，and what happens when they change.The word chemistry comes from chemical，which is an example of one type of the very small things that other bigger things are made of.The words you are reading now are made of a dark liquid called ink （墨水），which is written on paper.The paper itself is made out of the chemicals that wood is made out of.Both the ink and the paper were made by different chemical processes.A chemical process is what happens when chemicals come together to make other chemicals，and therefore other things.
Cooking makes chemical changes.Your different ingredients are made of different chemicals，and when you put them together and make them hot and cook them，the chemicals change into new chemicals and the different ingredients make something new.That tomato sauce you're making is made of tomatoes，onions，garlic，salt and pepper.Those ingredients each have their own chemicals and their own flavors，but now with your sauce you've made something different，something that has its own flavor，all the ingredients mixed together，all the chemicals mixed together，something new.
You can smell the chemical changes，too，as they go up into your nose，especially when you forget about your sauce and it doesn't just cook but bums and becomes black and has a really bad flavor.You can't make it better，either，because once chemicals change，they can't be changed back again.
（1）What does the underlined word "they" in Paragraph 2 refer to？ C
A.Chemistry.
B.Chemical.
C.The smallest things.
D.The bigger things.
（2）What is a chemical process？
A.Ink is written on paper.
B.Paper is made out of wood.
C.Everything is made of something.
D.Things mixed together produce something new.
（3）What does Paragraph 3 mainly talk about？ D
A.How to make tomato sauce.
B.What to use to form new things.
C.Ingredients and their own flavors.
D.Chemical changes in cooking food.
（4）Which might be the best title for the text？ D
A.What chemistry is like.
B.Chemistry changes everything.
C.Where the word chemistry comes from.
D.A chemical process is called chemistry.
【分析】本文主要介绍了发生化学变化的过程叫做化学。
【解答】（1）C.词义猜测题。根据Chemistry is about the smallest things that other bigger things are made of，and what happens when they change.可知化学是关于其他更大的东西所组成的最小的东西，以及当它们改变时会发生什么。根据前后文含义以及结合选项可知，此处they指的是"最小的事物"，故选D.
（2）B.细节理解题。根据The paper itself is made out of the chemicals that wood is made out of.可知纸张本身是由木材所用的化学物质制成的。故选B.
（3）D.段落大意题。根据 Cooking makes chemical changes.Your different ingredients are made of different chemicals，and when you put them together and make them hot and cook them，the chemicals change into new chemicals and the different ingredients make something new.可知烹调会产生化学变化。你的不同配料是由不同的化学物质组成的，当你把它们放在一起加热烹调时，化学物质会变成新的化学物质，不同的配料会产生新的东西。因此可知第三段主要介绍了烹饪食物中的化学变化。故选D.
（4）D.标题归纳题。通读全文，尤其是根据Chemistry is about the smallest things that other bigger things are made of，and what happens when they change.The word chemistry comes from chemical，which is an example of one type of the very small things that other bigger things are made of.化学是关于其他更大的东西组成的最小的东西，以及当它们改变时会发生什么。化学这个词来自化学，它是其他更大的东西组成的一种非常小的东西的一个例子。以及A chemical process is what happens when chemicals come together to make other chemicals，and therefore other things.化学过程是指化学物质结合在一起形成其他化学物质，从而形成其他东西的过程。可知本文主要介绍了发生化学变化的过程叫做化学。所以标题为"A chemical process is called chemistry."最为适合。故选D.
【点评】做题时首先对原文材料迅速浏览，掌握全文的主旨大意．其次，细读题材，各个击破。掌握全文的大意之后，细细阅读材料后的问题，弄清每题要求后，带着问题，再回到原文中去寻找、捕获有关信息。
