题目内容：
根据以下材料回答第 1～4 题：How can we get rid garbage?Do we have enough energy sources to meet our futureenergy needs?
These are two important questions that many people are asking today．Some peoplethink that man might be able to solve both problems at the same time．They suggest using garbage as an energy source，and at the time it can save the land to hold garbage.
For a long time，people buried garbage or dumped it on empty land．Now，empty land is scarce．But more and more garbage is produced each year．However，garbage can be a good fuel to Ltse．The things in garbage do not look like coal，petroleum'or natural gas； but they are chemically similar to these fossil fuels．As we use up our fossilfuel supplies’ we might be able to use garbage as an energy source．Burning garbage lS not a new idea. Some cities in Europe and the United States have been burning garbage for years．The heat that is produced by burning garbage is used to boil water．The steam that is produced is used to make electricity or to heat nearby buildings．In Paris，France，some power plants burn almost 2 million metric tons of the cities garbage each year．The amount of energy Produced js about the same as would be produced by burning almost a half million barrels of oil．
Our fossil fuel supplies are limited．Burning garbage might be one kind of energy source that we can use to help meet our energy needs
What two problems can man solve by burning garbage?
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