题目内容：

 

Cars	Cars are getting bigger. Bigger cars burn more gas and increase(增加) problems with air pollution. So try to walk， ride， or take buses or subways. And if you drive a car， keep it in a good state. This can save gas and make less pollution.
Energy	The biggest use of energy is for heating and cooling. So turn up your air conditioner（空调） and turn down the heat（加热器）， especially at night. Use energy-saving lights. And remember to turn lights off.
Products（产品）	Each American family throws away about 10 kilograms of litter every day. Try to make less waste. Ask yourself before you buy something： Do I really need it? Buy products that you can reuse(重复使用).
Water	Showers use a lot of water. Take shorter showers or buy a special small shower head. This can cut water use in half.

阅读以上信息，用恰当的词完成下面的短文，每空一词。

    There are some things we can do to help the environment. The size and weight of cars

1.  the use of gas. Driving smaller cars use less gas than bigger ones. Walking and riding

2. need any gas. These can reduce air pollution. Using air conditioner and the heat_3._can

save energy. Buying products that can be used   4. can make less litter. Taking shorter shower is a good way to save water. Buying a special shower head can also   5. cut water use.