题目

一定量的CuS和Cu2S的混合物投入足量的HNO3中，收集到气体VL（标准状况），向反应后的溶液中（存在Cu2+和SO42-）加入足量NaOH，产生蓝色沉淀，过滤，洗涤，灼烧，得到CuO 12.0g，若上述气体为NO和NO2的混合物，且体积比为1﹕1，则V可能为(    ) A．9.0 L       B．13.5 L         C．15.7 L      D．16.8 L 答案：A用括号内所给单词的适当形式填空1. I met an old friend of __________(I) on my way home yesterday.2. These skirts all look nice. It's hard for me __________(choose).3. I want to improve my reading skills. Could you give me some __________(advice)?4. I'm sure she can improve __________(her) in spoken English in two years' time.5. The company expects __________(finish) work in August.