A:CH4和NH4+
B:CO32﹣和NO3﹣
C:CO和N2
D:H2O和CH4
果实由____和____组成。
绿色化学就是从源头上消除对环境的污染,下列措不施符合绿色化学理念的是( )
—Where's Sam?
—He _______ for a test in his room.