2020 Shanghai Question 6 Single-choice Differentiating 2020_上海 Paper 6.钥匙从距水面20m 高的桥面自由落下,竹筏前端在钥匙下落瞬间正好位于正下方。该竹筏以2.1m/s的速度匀速前进,若钥匙可以落入竹筏中,不考虑竹筏的宽度,则竹筏至少长( ) A. 2mB. 4mC. 6mD. 8m Answer keyB ☆ SaveCan't do it, show the explanation查看原卷 →