Scientists have discovered that the ozone layer is getting thinner. Some predict that the sun’s rays will cause a sharp increase in deaths from skin cancer over the next fifty years. These harmful rays can also damage the eyes, create wrinkles, and cause other health problems. The stratosphere contains a form of oxygen called ozone. Ozone is a molecule composed of three oxygen atoms. The chemical formula of ozone is 03. Oxygen molecules make up about 21% of all gases in the Earth’s atmosphere. They consist of two atoms of oxygen and are labeled 02. Most ozone found in our atmosphere is formed by an interaction between oxygen molecules and ultraviolet radiation (UV) from the sun. When ultraviolet radiation hits an oxygen molecule, it may cause the molecule to break apart into single atoms of oxygen. These single atoms are very reactive, and a single oxygen atom can combine with a molecule of oxygen to form ozone. 1. What do people say about the rate of deaths from skin cancer in the future? A. It will decrease sharply B. It will remain stable C. It will increase sharply D. It will flutuate 2. How many oxygen atoms are there in a molecule? A. three oxygen atoms B. two three oxygen atoms C. a lot of oxygen atoms D. no oxygen atoms 3. How is ozone formed in our atmosphere? A. Two single atoms of oxygen interact each other. B. Two oxygen molecules interact each other. C. One oxygen molecule interact with one carbondioxide. D. One single oxygen atom combines with a molecule of oxygen 4. What does the word “ they” in the second paragraph refer to? A. Ozone molecules B. Gases C. the Earth’s atsmosphere D. Oxygen molecules 5. The word INCREASE in the first paragraph means …………. A. go down B. go up C. stay unchanged. D. vary continuously