既能活血，又能凉血的药物是
A．大黄
B．赤芍
C．丹皮
D．紫草
E．茜草
参考答案：A,B,C,D,E
Helen and her friends ______ football every afternoon. [ ]
A. play
B. plays
C. is playing
D. are playing
捣固车使用激光拨道作业时，采用（）检测。
A、三点式
B、四点式
C、三点式或四点式
D、激光式
