Help to some fish, children.
A:yourself
B:your
C:yourselves
若2a3xby+5与5a2﹣4yb2x是同类项,则x=____;y=____.
①0.1mol/L的氨水可以使酚酞试液变红
②0.1mol/L的氯化铵溶液的pH约为5
③在相同条件下,氨水溶液的导电性比强碱溶液弱
④铵盐受热易分解.
——Lucy is in front of Lily and Mike is behind Lily.——So we can say Lily is______ Lucy and Mike.
汉代以来,人类文化的传播变得更加方便和快捷,最主要是因为( )