-- The windows are broken and need to be repaired.

-- I think so. They can hardly     the cold now.

A．keep out

B．give out

C．take out

D．put out

现有甲、乙、丙、丁四种金属，将这四种金属粉末分别投入相同浓度的盐酸中，只有丙、丁发生反应并产生气泡，而且丁产生气泡比丙的更快；将甲投入乙的硝酸盐溶液中，有金属乙析出。这四种金属的活动性顺序是[ ]

A．丁＞丙＞甲＞乙

B．乙＞甲＞丙＞丁

C．丙＞丁＞甲＞乙

D．丁＞丙＞乙＞甲