1．a.(2020·浙江卷) Kevin Balke, a research engineer at the Texas A&M University Transportation Institute, says that while smart lights can be particularly beneficial for some cities, others are so jammed that only a sharp reduction in the number of cars on the road will make a meaningful difference. 急剧的；明显的
b．(天津卷)The link between what the men had done as boys and how they turned out as adults was surprisingly sharp. 明确的；确定的
2．(2018·全国卷Ⅱ)While the decline over the past decade is steep for teen readers, some data in the report shows that reading remains a big part of many children's lives, and indicates how parents might help encourage more reading. (数量的上升或下降)急剧的
3．(天津卷)Parents and children should communicate more to narrow the gap between them so that they can understand each other better. 缩小
