题目

When you want to go shopping, decide how much money you can spend for new clothes. Think about the kind of clothes you really need. Then look for those clothes on sale(销售). There are labels(标签)inside all new clothes. The labels tell you how to take care of your clothes. The label for a shirt may tell you to wash it in warm water. A sweater label may tell you to wash by washing in cold water. The label on a coat may say dry clean only. Washing may ruin(损坏)this coat. If you do as the directions(说明)say on the label, you can keep your clothes looking their best. Many clothes为了预防传染病，救灾指挥部要配制浓度为18%的消毒液，现有浓度为20%的消毒液600毫升，需加水多少毫升？