下列现象和事实,可用金属活动性左右为难作出合理解释的是 ①金属镁在空气中比铝更易点燃,说明镁比铝活动性强 ②金属铝比金属锌更耐腐蚀,说明锌比铝活动性强 ③硫酸铜、石灰水配制农药波尔多液,不宜用铁制容器 ④金属锌与稀硫酸反应速率适中,更适于实验室制取氢气 A.①② B.③④ C.①③④ D.①②③④用动词的适当形式填空
________ you ________ (have) a test in English last week?
Yes, we did.
________ you ________ (get) full marks?
No. I ________ (make) some mistakes. I think I ________ (do) better next time.