今天我们要学的词是toughen。 Toughen, 作为动词，意思是变得强硬起来。 "Egypt canceled plans to toughen visa restrictions on tourists after travel companies said the new rules would drive visitors away," 埃及放弃了加强旅游签证控制的计划，因为旅游公司说，这样做会赶走游客。 "China’s top court plans to toughen sea pollution penalties," 中国最高法院将加强对海洋污染行为的惩罚。九月初， "President Obama scrapped a rule that would have toughened air quality standards," 美国总统奥巴马撤销了一项原本将加强对空气质量标准要求的法规。好的，今天我们学习的词是toughen...