下列中草药中不含有香豆素的是（）
A.五味子
B.白芷
C.秦皮
D.独活
E.紫花前胡
参考答案：D
A cook will be immediately fired if he is found _____ in the kitchen. [ ]
A. smoke
B. smoking
C. to smoke
D. smoked
链斗挖泥船顺流施工时后边锚宜滞后（）左右。
A.5°
B.10°
C.15°
D.20°
