题目

铋(Bi)位于元素周期表中第ⅤA族，其价态为＋3时较稳定，铋酸钠(NaBiO3)溶液呈无色。现取一定量的硫酸锰(MnSO4)溶液，向其中依次滴加下列溶液，对应实验现象如表所示： 加入溶液①适量铋酸钠溶液②过量的双氧水③适量KI­淀粉溶液 实验现象溶液呈紫红色溶液紫红色消失，产生气泡溶液变成蓝色 则NaBiO3、KMnO4、I2、H2O2的氧化性由强到弱的顺序为( ) A.I2、H2O2、KMnO4、NaBiO3 B.H2O2、I2、NaBiO3、KMnO4 C.NaBiO3、KMnO4、H2O2、I2 D.KMnO4、NaBiO3、I2、H2O2完形填空Swimming is very popular in summer. People like swimming in summer because water makes them1cool. If you like swimming but swim in a2place, it may not be safe. These years, more than ten people3 while they were enjoying themselves in the water and4of them were students. But some people are5not careful in swimming. They often think they swim so6that nothing can happen to them in water. Summer is here again. If you go swimming in summer, don't forget7better swimmers have died in water. They died because they were not careful, not because they 8swim. So don't get into water when you are alone.9there is a "No Swimming" sign, don't get into water,10. If you remember these, swimming will be safer.（1）A.felt B.feel C.feeling D.to feel （2）A.difficult B.small C.right D.wrong （3）A.died B.die C.have died D.will die （4）A.much B.most C.lot D.more （5）A.yet B.already C.still D.even （6）A.fast B.often C.well D.hard （7）A.what B.that C.which D.who （8）A.couldn't B.wouldn't C.needn't D.mustn't （9）A.Because B.Though C.Whether D.If （10）A.either B.nor C.also D.Too