题目

一轻弹簧上端固定，下端挂一物块甲，甲和乙用一细线相连，如图所示，甲的质量为2m，乙的质量为m，两者均处于静止状态．当甲、乙之间的细线被剪断的瞬间，甲、乙的加速度大小记作a甲、a乙，那么(   ) 答案：B10、--- The research is difficult. Who do you think can do the job? ---       my students have a try? A．Will          B．Shall           C．Must           D．May