A：Na+、I－、NO3－、MnO4－
B：Mg2＋ SO42- NH4+ Cl-
C：K＋ Na＋ OH- Cl-
D：K＋ Ca＋ NO3- HCO3-
甲每日都用不锈钢锅炒菜，乙则用铁锅．甲比乙更易患的病是（ ）
The Greens ________live in the south of Asia . They don't want to move to the north because they ________ the cold weather.
“若a>1，则a2>1”的逆否命题是____，为____(填“真”或“假”)命题．
某电影爱好者准备暑假期间到世界电影之都去参观学习,以下哪个地区是他的首选地( )
