如图,将纯Fe棒和石墨棒插入1 L饱和NaCl溶液中。下列说法正确的是( )
A.M接负极,N接正极,当两极产生气体总量为22.4 L(标准状况)时,生成1 mol NaOH |
B.M接负极,N接正极,在溶液中滴人酚酞试液,C电极周围溶液变红 |
C.M接负极,N接正极,若把烧杯中溶液换成1 L CuSO4溶液,反应一段时间后,烧杯中产生蓝色沉淀 |
D.M接电源正极,N接电源负极,将C电极换成Cu电极,电解质溶液换成CuSO4溶液,则可实现在铁上镀铜 |
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 |
It is often ______ that human beings are naturally equipped to speak.
A.said | B.to say | C.saying | D.being said |
I can’t leave. She told me that I ______ stay here until she comes back.
A.can | B.must | C.will | D.may |