造成生物多样性丧失的原因主要有_______________和_________。
人口的快速增长 环境污染
责任保险产生于（）世纪的欧美国家。
A.17
B.18
C.19
D.20
A good article should not only be rich in the use of language, but also it ought to be ________ organized.
A．personally
B．faithfully
C．unexpectedly
D．logically
