From the two charts we can see that in the past ten years, students who go traveling and do social investigations during the summer vacation have greatly increased while those who stay at home have decreased a lot.　　

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There are several reasons for the changes. Firstly, with the development of economy, students can get support from their parents for traveling. Secondly, tourism has greatly developed over the past ten years. In addition, school has been encouraging students to do social investigations in both cities and villages.　　

From the changes we can predict that more and more students will make their summer vacation colorful and meaningful by going outside instead of staying at home.