下列叙述正确的是:①锌跟足量稀硫酸反应时,加入少量硫酸铜溶液能加快反应速率且不影响产气量 ②镀层破损后,白铁(镀锌的铁)比马口铁(镀锡的铁)更易腐蚀 ③电镀时,应把镀件置于电解槽的阴极 ④冶炼铝时,可以电解熔融态的AlCl3 ⑤钢铁表面常易锈蚀生成Fe2O3·nH2O
If you leave the club, you will not be_____back in .
What I need is_____ book that contains ______ABC of oil painting.
Jenny nearly missed the flight______ doing too much shopping.
The CDs are on sale! Buy one and you get ______ completely free.
I’m sure that your letter will get______ attention. They know you’re waiting for the reply.