题目

如图所示倾角θ=30°的固定斜面上固定着挡板，轻弹簧下端与挡板相连，弹簧处于原长时上端位于D点．用一根不可伸长的轻绳通过轻质光滑定滑轮连接物体A和B，使滑轮左侧绳子始终与斜面平行，初始时A位于斜面的C点，C、D两点间的距离为L．现由静止同时释放A、B，物体A沿斜面向下运动，将弹簧压缩到最短的位置E点，D、E两点距离为．若A、B的质量分别为4m和m，A与斜面的动摩擦因数μ=，不计空气阻力，重力加速度为g，整个过程中，轻绳始终处于伸直【1】I’m good at _______(地理). What about you, Jenny?【2】Would you like to come to our party _______(今晚)?【3】Jane will come back in a _______(一刻钟). Please wait a moment.【4】When the child saw his mother, he_______(冲) to her quickly.【5】Danny, you shouldn’t _______(喊) loudly in the library.