题目

People are advised to be            towards the health concerns of their dear ones while burning firecrackers to celebrate the festival, for they contain harmful chemicals. A．accessibleB．awareC．cautiousD．sensitive 答案：D已知还原性Cl－＜Fe2+＜H2O2＜I－＜SO2，判断下列反应不能发生的是A．2Fe3++SO2+2H2O＝SO42－+4H++2Fe2+     　B．I2+SO2+2H2O＝H2SO4+2HIC．H2O2+2H++SO42－＝SO2+O2+2H2O          D．2Fe3++2I－＝2Fe2++I2