cost(cost cost) health opportunity 动名词作主语 现在完成时

encounter opportunity 不定式作宾语补足语 关系代词which引导限制性定语从句 情态动词(not)+动词原形

challenge crisis finally glory opportunity a number of in the face of 介词与其它词类的搭配 一般过去时 不定式的一般式：to+动词原形

help opportunity service volunteer 动名词作主语 一般现在时 participate in

challenge company individual necessary opportunity 一般现在时 可数名词的单复数 bring about up to

achieve challenge opportunity overcome(overcame overcome) seize though work(奏效；起作用) be sure to do sth. 现在完成时 让步状语从句 语法一致

dedication opportunity service make a difference 一般现在时 连接代词和连接副词引导的宾语从句 语法一致

age opportunity go abroad 一般现在时 语法一致 关系代词who引导限制性定语从句