题目

除去铜粉中混的有少量氧化铜，其主要操作过程是（   ） A.在空气中燃烧                      B.加适量稀硫酸、微热、过滤 C.加适量水、微热、过滤              D.加适量稀硫酸、微热、蒸发 答案：B 【解析】考查物质的分离与提纯。氧化铜能溶于酸中，而铜不能，据此可以除杂，所以答案选B。Most people make their living with their hands. But Tom makes his living(谋生）with his feet. A very good living it is, too.Tom’s story began in a very small city in England. His parents were very poor. Seven people lived in their small house. Tom had no place to play in but in the street.Tom’s father often played football, and little Tom wanted to play football, too. So his father made a nice ball for him to play. The little boy played it every day.At last Tom learned to play a real football, and after a few years he could play football very well.Now Tom is one of the best football players.1.Tom made his living with his______A.handsB.headC.feet2.Tom’s parents lived in a_____city in EnglishA.smallB.bigC.new3.Tom’s father____a football for him to playA.boughtB.borrowedC.Made4.A few years later, Tom was_____at playing footballA.wellB.goodC.bad5.Tom plays football_____ than many other playersA.harderB.worseC.better