UNIT 09 Oxygen

　　Can you touch or feel oxygen in the air? Oxygen has very unique characteristics. You cannot see oxygen, because it doesn’t have a color. Also, oxygen does not melt in water. Oxygen doesn’t have a smell. However, it helps burn other things. Can you live without oxygen? Definitely not! We cannot live without oxygen even for more than a few minutes。

　　Select True or False

　　❶ People can see oxygen. (T/F)

　　❷ Oxygen has a smell. (T/F)

　　❸ People can not live without oxygen. (T/F)

　　More to know

　　within

　　within有“在……内”的意思。与表示地点、时间、距离的词用在一起。

　　··We need to finish this work within a week。

　　我们要在一个星期内完成这项工作。

　　··Please call me back within 10 minutes。

　　请10分钟内给我回电话吧。

　　READING COMPREHENSION

　　*Read and circle the best answer。

　　❶ What is a unique characteristic of oxygen?

　　a. It has no smell。

　　b. It can be seen。

　　c. It melts in water。

　　❷ What can oxygen do?

　　a. It can buy things。

　　b. It can help burn things。

　　c. It can change things。

　　*Complete the sentence with the right answer。

　　❸ You cannot see oxygen, because it doesn’t have a 。

　　a. color b. smell c. taste

　　❹ People cannot live without even for more than a few  minutes。

　　a. water b. oxygen c. food

　　DESCRIBE THE PICTURE

　　*Unscramble the words in the box。

　　The diver the water under is

　　潜水员在水下潜水。