A、Growing population. B、Packaging materials. C、Changed eating habits. D、Lower production cost. B对话中男士说十年或二十年前，人们所使用的包装材料本身就是可以回收

W: Why is it important to recycle?
M: There are many reasons. Recycling is one way to keep waste out of landfills. Landfills are places to dump waste.(9)But they are unpopular, because they can pollute the soil used to cover them and that’s bad for people who may build new homes there. Recycling also reuses valuable raw materials, such as aluminum and paper. Finally, recycling can leave a lower garbage bill. Recycling lowers the amount of waste put into landfills, therefore, less money is spent for garbage disposal.
W: How has recycling changed over the years?
M:(10)Ten or twenty years ago, you could buy milk in returnable, refillable glass bottles, and many people recycled voluntarily. Now you buy milk and other products in plastic bottles or paper containers. Because of the high cost of disposing of these things in landfills, many city governments now have recycling programs.
W: How does recycling help the environment?
M:(11)Recycling helps the environment mainly by saving energy. For example, it takes 95 percent less energy to produce recycled aluminum than to produce new aluminum.
W: Can one person really make a difference? If only a few people recycle, then what’s the point?
M: If not you, then who?(12)If we combine our efforts, we can make a difference. Each of us contributes to the waste problem. All the millions of tons of waste that go into landfills started as an old pair of slippers, a broken TV set, or a used magazine that came from somebody’s house—maybe yours!
9. Why are landfills unpopular according to the man?
10. What does the man say has contributed to the increasing amount of waste over the years?
11. According to the man, how does recycling help the environment?
12. Why does the man say everybody should make an effort to recycle?