1.（2019全国II卷） I work not because I have to, ______ because I want to.”
【答案】but
【解析】考查并列连词。根据句意逻辑可知，此处为转折关系，句意：我工作不是因为我不得不做，而是因为我想做。此处用but与前文not 呼应，构成“不是…而是 …”之意，故填but。
2．(2018·全国Ⅲ卷)When the gorillas and I frightened each other, I was just glad to find them alive. True to a gorilla's unaggressive nature, the huge animal________ (mean) me no real harm.
【答案】meant
【解析】考查简单句。根据语境可知此处叙述的是发生在过去的事情，应该用一般过去时，故填meant。
3．(2017·全国Ⅱ卷)This included digging up the road, ________ (lay) the track and then building a strong roof over the top.
【答案】laying
【解析】laying和句中的digging up, building并列。句意：这包括在公路上挖掘，铺设轨道，然后在顶部建造一个坚固的屋顶。
