biologist challenge impress all the time take up 一般现在时 主语从句的连接词 连接代词和连接副词引导的表语从句 语法一致

cause infection contribute to lead to result in subscribe to 一般过去时 一般过去时的被动语态 主语从句的连接词 that, whether, as, as if, as though, because引导的表语从句

become(became become) often run(ran run) a lot 一般现在时 that, whether, as, as if, as though, because引导的表语从句 语法一致 关系副词why引导限制性定语从句

academic influence inspiring 一般现在时 that, whether, as, as if, as though, because引导的表语从句 关系副词why引导限制性定语从句

chew feel mean adj.吝啬的 end up 主语从句的连接词 that, whether, as, as if, as though, because引导的表语从句 原因状语从句 关系代词who引导限制性定语从句

replace 连接代词和连接副词引导的表语从句 表语从句的时态

wake up 动名词作主语 介词与其它词类的搭配 一般过去时 that, whether, as, as if, as though, because引导的表语从句 虚拟语气用于as if/though引导的表语从句 as if