define /dɪˈfaɪn/ v.给……下定义，解释；阐明
define /dɪˈfaɪn/ v.给……下定义，解释；阐明
真题复现1：In other words, at a time when the working class has turned the country on its political head, frustrated that the opportunity that once defined America is vanishing, one obvious solution is staring us in the face.（2018英二，Text 1）
真题翻译：换句话说，在一个工人阶级彻底改变了美国政治思路、并对曾经定义美国的机会正在消失而感到挫败的年代，一个显而易见的解决方案就摆在我们面前
真题复现2：The role that weather plays in formation flight has not yet been clearly defined.（2010英二，新题型）
真题翻译：天气在编队飞行中所起的作用尚未得到明确界定。
真题复现3：Of even greater concern is the fact that obesity turns out to be very difficult to define.（2014英二，完形）
真题翻译：更令人关注的是，肥胖其实很难界定。
frustrate 使懊恼，使沮丧；挫败，阻挠
vanish 突然不见，消失；不复存在
formation flight [航] 编队飞行
obesity 过度肥胖，肥胖症
turn out to be 结果是；原来是
