题目

While listening, remember that it is not __________ to listen only with your ears; you must listen with your brain as well. A. substantial           B. sufficient               C. considerable        D. consistent 答案：B关于加速度，下列说法正确的是A.是速度的变化量B.与速度的变化量成正比，与时间成反比C.是速度的变化率D.与速度的变化率成正比，与时间成反比