问题补充：
from other continents for millions of year, Australia has many plants and animals not found in any other country in the world.
A. Being separated
B. Having been separated
C. Having separated
D. To be separated
答案：
A. Being separated
(答案→)B. Having been separated
C. Having separated
D. To be separated
解析：考查现在分词的完成式：句意：被和其他大陆分开上百万年后，澳大利亚有很多植物和动物在其他洲是找不到的。逗号后面的部分是主句，前面这一部分只能是状语．作状语的非谓语动词逻辑上的主语应是主句的主语，即Australia．“分割开”这个动作发生在很久以前而且与其逻辑主语是被动关系，这样就需要用分词的完成被动式，故B对．
