生物碱.黄酮类和萜类化合物

从化学结构来看，萜类是异戊二烯的聚合体及其衍生物，下列化合物中不属于萜类的是（）

A.龙脑

B.青蒿素

C.乌头碱

D.薄荷醇

E.樟脑

Google's complaints about hacker attacks on its servers (服务器) made the public more concerned about

the problem of Internet safety. ____, it called for changes in recent Chinese laws. [ ]

A. However

B. Otherwise

C. Therefore

D. Though