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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.

   Garbage is a big problem all over the world. People buy and use a lot of things nowadays. After a while, they throw them away in the garbage bin. All the garbage is later thrown away or dumped outside the city. These places are called landfill sites. In many cities, landfill sites are now full.

   We have to manage our waste and garbage better. If we throw away so many things, soon we will have no place to dump them. The best thing to do is to reduce the amount of garbage. If we use less, we throw away less. For instance, we can buy food in big boxes and packages. Then we throw away only one box every month or so. Otherwise, we throw away many small boxes or cans every day.

   Similarly, we can reuse a lot of packaging. For example, we do not have to buy take-out coffee in Styrofoam cups, which are made of aluminum - a toxic material to the environment. We can bring our own cup from home and fill it with fresh coffee.

   We also do not have to take the plastic bags from the supermarket. We can bring our own cloth bag from home instead. When we pack lunch, it is better to use a lunch box than a paper bag. Instead of paper plates, we can use real plates. We can clean up with a dishtowel, not a paper towel. We can use a compost bin for food scraps. In this way, the food gets back into the earth. It does not get mixed up with the regular garbage.

   Finally, all paper, glass and metal we do use, we can recycle. In many countries, there are now recycling programs. In Germany, for example, people separate all glass bottles by color. Then they put the bottles into special bins that are on the street. The city collects the glass, cleans it, and reuses it. As well, in most countries, people recycle newspapers and cardboard. It is easy and efficient.

(Source: http://mini-ielts. com/869/reading/the-garbage-problem)

Why does the author say that garbage is a big problem?

A. Because not all cities have landfill sites.

B. Because people throw away everything they buy.

C. Because landfill sites get fewer and fewer.

D. Because people buy too many things.