除去下列物质中所含杂质（括号内为杂质），所选用的试剂及操作方法均正确的一组是（ ）
| 选项 | 待提纯的物质 | 选用的试剂 | 操作方法 |
| A | MnO2（KCl） | 水 | 溶解、过滤、结晶 |
| B | CO2（CO） | 氧气 | 点燃 |
| C | Cu（CuO） | 稀盐酸 | 溶解、过滤、洗涤、干燥 |
| D | CuSO4（H2SO4） | 氢氧化钠溶液 | 过滤 |
A．A
B．B
C．C
D．D
A、MnO2混有杂质KCl，根据KCl可溶，操作方法应该是：溶解、过滤、洗涤、干燥．故选项错误；
B、二氧化碳中混有一氧化碳，通入氧气点燃后易混入氧气杂质．故选项错误；
C、Cu混有杂质CuO，用稀盐酸可以除去氧化铜，符合除杂质的条件，溶解、过滤、洗涤、干燥后能得到铜．故选项正确；
D、CuSO4混有杂质H2SO4，用氢氧化钠溶液时除杂时，不仅与硫酸反应，也与硫酸铜反应，不符合条件一．故选项错误；
故选C．
In China，a lot of food is wasted every year and the waste food is enough for people. The food is wasted in restaurants, at home and in schools, etc． In restaurants or at home，people often order or cook food. But they can’t eat it up. When they go out of a restaurant, full and happy, they never look back the uneaten food on the table again．Should Chinese consumers（消费者）feel for the terrible waste? In schools, we can often see a lot of students food away after meals and they only eat the food they like． Everyone is supposed to have enough food to eat. However, in some places, the food is so little a lot of people died from hunger．Although China has tried hard to solve the of hunger over the past thirty years，the job is not finished yet．Food is important to us all．We can’t live food．So is necessary for us to love food and try to eat up everything on our plates．When we eat in restaurants，we should pack up the leftovers（剩菜剩饭）．we also need to tell other people to stop food as soon as possible．
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