6.香豆素分子中的双键可分为：①C3-C4双键，②侧链双键，③呋喃或吡喃环中双键。双键加成反应能力的强弱顺序是

A.①>②>③                                                     B.②>③>①  

C.③>②>①                                                     D.③>①>②

7.下列黄酮类化合物几近无色的是

A.黄酮醇                                                         B.查耳酮      

C.花色素                                                         D.二氢黄酮

8.环烯醚萜属于______类化合物。

A.单萜                                                             B.倍半萜      

C.二萜                                                             D.三萜

9.遇碱性溶液显红色的化合物是

A.羟基蒽酮类                                                  B.羟基蒽醌类      

C.羟基蒽酚类                                                  D.二蒽酮类

10.下列基团中可使生物碱碱性增强的是

A.双键                                                             B.苯基  

C.羟基                                                             D.甲基

11.提取分离游离香豆素可用

A.酸溶碱沉法                                                  B.碱溶酸沉法      

C.醇提水沉法                                                  D.水提醇沉法

12.按苷的不同分类方式，苦杏仁苷属于

A.氰苷                                                             B.醇苷  

C.酯苷                                                             D.次生苷

13.可用于检测甲型强心苷的试剂是

A.碱性苦味酸                                                  B.三氯化铁-冰醋酸

C.过碘酸-对硝基苯胺                                       D.乙酐-浓硫酸

14.不符合皂苷通性的是

A.大多为白色结晶                                           B.味苦而辛辣

C.对粘膜有刺激性                                           D.振摇后能产生泡沫

15.提取某些贵重的挥发油，常选用的方法是

A.吸收法                                                         B.蒸馏法      

C.压榨法                                                         D.溶剂提取法