萜类化合物广泛分布于自然界,它们的碳骨架大多是由( )单位头尾相连而成。
A. 异戊二烯;
B. 丁二烯;
C. 苯乙烯;
D. 丙烯。
17岁男患者。诊断为右股骨下端内侧长蒂状骨软骨瘤。3天前跌倒后,出现局部疼痛,伴膝关节活动轻微受限。其原因是
A. 骨软骨瘤恶变
B. 骨软骨瘤基底部折断
C. 骨软骨瘤周围出现滑囊炎
D. 局部软组织挫伤
E. 骨软骨瘤外层软骨帽损伤
All the following are novels written by Jane Austen EXCEPT().
A. Mansfield Park
B. Shirley
C. Emma
D. Persuasion
The Head of State of Canada is represented by().
A. the Monarch
B. the President
C. the Prime Minister
D. the Governor-General