为了达到污水净化的目的,在污水处理厂的曝气池中存在的微生物是 [ ]
A.青霉菌和曲霉菌
B.链球菌和酵母菌
C.某些杆菌和甲烷细菌
D.某些球菌和甲烷细菌
答案:C
下列离子方程式正确的是( )
A.醋酸溶液中滴入少量氢氧化钠溶液:H++OH-=H2O
B.在小苏打溶液中滴入少量的氢氧化钡溶液:2HCO3-+Ba2++2OH-=2BaCO3↓+2H2O
C.硫酸铵溶液与氢氧化钡溶液混合加热:NH4++OH- △ . NH3↑+H2O
D.锌与稀硝酸反应:Zn+2H+=Zn2++H2↑
The reference she made to her friend, the poet, was interesting but too _____ for anyone to appreciate.
A.drastic
B.dull
C.obscure
D.distinct。