资源介绍：
DK English for Everyone:Business English Level 1+Level 2 PDF，其中第二个级别有练习册
本站还有另外两套DK English For Everyone
DK English for Everyone Vocabulary Builder 地址：http://www.v5mama.com/longman/2020-01-28/1793.html
DK English for Everyone Grammar Guide 地址：http://www.v5mama.com/longman/2020-01-28/1792.html
