A:抽签法
B:系统抽样法
C:分层抽样法
D:随机数法
环境中影响生物形态、生理、分布的因素称为____.它又分为____和____.
生动的展现了长江流域原始农耕图景的是——原始居民生活的( )
Mo Yan's books have been sold out in many bookstores ____ his winning of the Nobel Literature Prize.