A:63个
B:62个
C:17个
D:16个
The population of the world is ____ (increase) by 80 million every year.
1﹣溴丙烷和2﹣溴丙烷分别与NaOH的乙醇溶液共热的反应中,两反应( )
假定一个草原是由鹿和狼组成的相对封闭的生态系统,若把狼杀绝,鹿群的数量将会( )