问题
选择题
He made up an excuse for his mistake in order to avoid_________.
A.punishing
B.to punish
C.to be punished
D.being punished
答案
答案:D
avoid doing sth .避免做某事;且主语He和punish 是动宾关系,所以用doing的被动式,选D。
He made up an excuse for his mistake in order to avoid_________.
A.punishing
B.to punish
C.to be punished
D.being punished
答案:D
avoid doing sth .避免做某事;且主语He和punish 是动宾关系,所以用doing的被动式,选D。
已知25℃时有关弱酸的电离平衡常数:则下列有关说法正确的是( )
弱酸化学式 | CH3COOH | HCN | H2CO3 |
电离平衡常数 | 1.8×10-5 | 4.9×10-10 | K1=4.3×10-7 K2=5.6×10-11 |
A.等物质的量浓度的各溶液pH关系为:pH(NaCN)>pH(Na2CO3)>pH(CH3COONa)
B.冰醋酸中逐滴加水,则溶液的导电性、醋酸的电离程度、pH均先增大后减小
C.Na2CO3和NaHCO3等物质的量混合溶液中,一定存在C(Na+)+c(H+)=c(OH-)+c(HCO3-)+2c(CO32-)
D.amol/LHCN溶液与bmol/LNaOH溶液等体积混合后,所得溶液中c(Na+)>c(CN-),则a一定大于b