都能与盐酸反应的金属组是( )
A.锌、铁、铜
B.铝、镁、铂
C.钠、锌、铝
D.锌、铁、汞
C
金属的活动性顺序表中氢以前的金属均能置换出酸(或水)中的氢,生成氢气。
A: You look very nice in your new dress today.
B: Oh, really? I it when it was on sale.
A.buy
B.bought
C.have bought
D.will buy
一般情况下,三相变压器的变比大小与外加电压的大小有关。()