腰痛初发急性期，常选用小剂量的（）以养血补血，温通血脉.
A.当归
B.蜂房
C.莪术
D.川芎
E.水蛭
参考答案：A, D
把90个数据分成四组，绘制成频数分布直方图，已知各小长方形的高的比为3：4：2：1，则第一小组的频率为（ ），第二小组的频数为（ ）．
As a laid-off worker, it is hard for her father to ______ the family, let alone send his children to key
schools. [ ]
A. bring up
B. raise
C. support
D. supply
