今天我们要学的词是expansion。Expansion 扩展，扩充。The Kennedy Arts Center unveiled a $100 million expansion plan. 肯尼迪艺术中心宣布扩展计划，耗资一亿美元。President Obama supported the expansion of H1B visas from 65,000 to 115,000 a year. 美国总统奥巴马支持将每年的外籍人员工作签证发放数量从六万五千个增加到11万五千个。The Pentagon is moving toward a major expansion of its cyber security force to counter increasing attacks on the nation's computer networks. 美国五角大楼计划扩充负责网络安全的人员和能力，抵御美国电脑系统受到的越来越多的攻击。好的，今天我们学习的词是 expansion, expansion, expansion...