1. Expand your world. Many discoveries in science, engineering and the arts mix ideas from different fields. Consider "The Two-String Problem." 拓展你的视野。许多理工和人文科学方面的发现都融合了不同领域中的思想。以"两绳问题"为例。
2. The petals of many flowers expand in sunshine. 要阳光下许多花的花瓣开放。
3. The company, which has its headquarters in New York, has three stores in New York, one in Canada and five in Spain. It plans to expand to three more U.S. cities this year. 该公司总部设在纽约,分店在纽约有三家,加拿大有一家,西班牙有五家,今年还计划在另外三座美国城市增设分店。