—First, cut up the apples, bananas and pears. And then. . .
A:When
B:Where
C:Why
D:How
Terry and his team members were the first how the disease spreads from animals to humans.
我国是一个缺水的国家,人均占有水资源为世界人均的1/4,淮北市人均占有水资源为全国人均的1/5,因而我市是一个极度缺水的城市,污水净化具有重要的意义。如图所示为小明设计的太阳能净水器,在污水净化过程中发生的物态变化是( )
函数y=1x+2中,自变量x的取值范围是( )