①酸性:HClO4>HBrO4>HIO4
②离子还原性:S2﹣>Cl﹣>Br﹣>I﹣
③沸点:HF>HCl>HBr>HI
④金属性:K>Na>Mg>Al
⑤气态氢化物稳定性:HF>HCl>H2S
⑥半径:O2﹣>Na+>Na>Cl.
A:①②③
B:②③④
C:①④⑤
D:①②③④⑤⑥
⑴____ A.Bund B.found C.Summer Palace D.Great Wall
⑵____ A.visited B.beside C.saw D.caught
⑶____ A.why B.where C.who D.did
⑷____ A.our B.we C.they D.he
⑸____ A.cloud B.windy C.rainy D.sunny
如图所示的四种现象中,由光的折射形成的是( )