常温下,下列各组离子在指定溶液中一定能大量共存的是
A.0.1 mol·L-1 NaOH溶液:K+、Na+、AlO2-、CO32- |
B.0.1 mol·L-1 Na2CO3溶液:K+、Al3+、NO3-、Cl- |
C.pH=3.5的溶液:K+、NH4+、I-、Fe3+ |
D.c(H+)/c(OH-)=1×1014的溶液:Ca2+、Na+、ClO-、NO3- |
I’m sure that your letter will get______ attention. They know you’re waiting for the reply.
A.continued | B.immediate | C.careful | D.general |
All the dishes in this menu, ______ otherwise stated, will serve two to three people.
A.as | B.if | C.though | D.unless |
The children loved their day trip, and they enjoyed the horse ride ______.
A.most | B.more | C.less | D.little |
Progress______ so far very good and we are sure that the work will be finished on time.
A.was | B.had been | C.has been | D.will be |
Charles was alone at home, with_______ looking after him.
A.someone | B.anyone | C.not one | D.no one |