题目

 I didn’t know how                to London?       A．would they go       B．are they going    C．they would go   D．they are going 答案：CX、Y代表两种非金属元素，下列不能说明非金属性X比Y强的是( )A．Y的阴离子Y—的还原性强于X的阴离子X— B．X的氢化物的水溶液的酸性比Y的氢化物的水溶液的酸性强 C．X的单质X2能将Y的阴离子Y—氧化成Y2D．X、Y的单质分别与Fe化合，产物中前者Fe为+3价，后者Fe为+2价