题目内容：

根据短文内容，用方框中所给单词的适当形式填空，每词限用一次。

   Have you heard of “car sharing”? The idea of “car sharing” is becoming more 1. in Europe and the USA. “Car sharing” is that people drive together in the same car to work, instead of 2. their own cars.

On average , we drive our cars only one hour every day. The rest of the time we 3. park our cars in parking places and we have to 4. too much money in parking our cars in the city. To save money and help the environment, people 5. to share cars several years ago. ”Car sharing” is a good way for us to save money, time, and help the environment at the same time. What a great idea!