与β-谷甾醇能形成稳定的沉淀的是（）
A.三萜皂苷
B.甾体皂苷
C.强心苷
D.C21甾类
E.酸性皂苷
参考答案：B
—_____ book is this?
—It _____ Anna.[ ]
A. Who; belongs to
B. Which; belonging to
C. Whose; belongs to
D. Whose; belonging to
市场=人口+购买力+购买欲望。
