dual settle exchange barter

例句：

1. 1. The dual purpose of the projectis to improve transportation and reduce pollution.
   该项目的双重目的是改善交通并减少污染。
2. 2. Thedual-use nature of nuclear energy makesit a controversial topic.
   核能的双重用途性质使其成为一个有争议的话题。
3. 3. The dual-language program aims to provide bilingual education for students from diverse backgrounds.
   双语项目旨在为来自不同背景的学生提供双语教育。