translation.en: The first is that this product works well because we were effectively able to combine rigorous engineering science and analysis with user-centered design focused on the social and usage and economic factors important to wheelchair users in the developing countries.
translation.zh: 第一点是项目成功的原因在于 我们有效地把严谨的工程科学 与以用户为中心的设计分析结合起来 聚焦于社会，利用和经济因素 这对发展中国家的轮椅使用者非常重要