________ of experience made John fail in the interview,but it didn't mean that he couldn't find a suitable job. A. Lacking B. Lack C. Lacking in D. No lack 答案:B一个摆在空气中做阻尼振动,下列说法中正确的是( ) A.系统的机械能在逐渐转化为其他形式的能 B.后一时刻摆球的动能一定比前一时刻摆球的动能小 C.后一时刻摆球的势能一定比前一时刻摆球的势能小 D.后一时刻摆球的机械能一定比前一时刻摆球的机械能小