说明：  我们选择研究世博会对上海市旅游业的影响，具体是从旅游业的客流量与旅游业投资两个方面入手搜集数据，进行定量分析。
(We choose to study the impact of the World Expo on Shanghai's tourism industry. We collect data and make quantitative analysis from two aspects: tourist flow and tourism investment.)