【简答题】The carpet on the floor was stained and torn, the windows nearly __________ with dirt, and the walls looked as if they had never been repainted since the place was constructed.
【简答题】某同学利用如图 5 - 3 - 15 甲所示装置做 “ 研究平抛运动 ” 的实验,根据实验结果在坐标纸上描出了小球水平抛出后的运动轨迹,但不慎将画有轨迹图线的坐标纸丢失了一部分,剩余部分如图乙所示.图乙中水平方向与竖直方向每小格的长度均代表 0.10 m , P 1 、 P 2 和 P 3 是轨迹图线上的 3 个点, P 1 和 P 2 、 P 2 和 P 3 之间的水平距离相等.完成下列填空: ...