具行补肾、活血、止血功效的药物是
A．阿胶B．三七C．狗脊D．骨碎补E．菟丝子
参考答案：D
体育课上，某班两名同学分别进行了5次短跑训练，要判断哪一名同学的成绩比较稳定，通常需要比较两名同学成绩的( )
A．平均数
B．方差
C．众数
D．中位数
Simon improved his way of study. ________, he has made great progress [ ]
A. As a result
B. As usual
C. In other words
D. In all
