1．(2020·全国卷Ⅱ)Some parents will buy any hightech toy if they think it will help their child，but researchers said puzzles help children with mathrelated skills.n.智力玩具
2．(2020·全国卷Ⅲ)And when he saw the mists rising from the river and the soft clouds surrounding the mountain tops，he was reduced to tears.vt.使……陷入某种状态中
3．(2019·全国卷Ⅰ) Modern methods of tracking polar bear populations have been employed only since the mid1980s，and are expensive to perform consistently over a large area.vt.使用
4．(2018·全国卷Ⅰ) Over the years，there have been a number of different techniques to help designers approach this important point.vt.着手处理
