治疗阴虚火旺型经行口糜的最佳方剂是：（）
A.左归丸
B.六味地黄丸
C.知柏地黄丸
D.杞菊地黄丸
E.左归饮
参考答案：C
We were prevented ________ the project on time by the bad weather. [ ]
A. to complete
B. completed
C. completing
D. from completing
简述酶提取过程的注意事项
