题目

下列设备应用到的物理知识解释错误的是 A．声纳系统——利用回声定位原理 B．电视遥控器——利用红外线实现电视机的遥控 C．验电器——两片金属箔带异种电荷而互相吸引 D．验钞器——紫外线使钞票上的荧光物质发光 答案：CIn the United States,a child under 16 can't have a full-time (全日制) job. If you are 14 or 15  years old,you can work part-time (部分日寸I、司) after school or on weekends,and in the summer holiday you can work 30 hours each week. Does all that mean that if you are under 14 ,you can't earn (赚) your own money? Of course not!Children between 10 to 13  years old can earn money by doing lots of things.Valerie,11. tells us that she makes money by cleaning up other people's yards (院子) . Lena,13, makes money by knitting (会只) dog sweaters and selling (卖) them to her neighbours. Reisa says she is good at drawing and sells her pictures to people. Jasmine,13, writes articles for different children's magazines!Earning is learning. By working to earn your own money, you are learning important skills. These skills will help you succeed (成功) in the future. These skills can include things like how to work with others,how to use technology (技术) and how to plan your time.To think about how you can make money,ask yourself:. What special skills do I have?. How do I enjoy spending my time? -. Do my friends,family,or neighbours need help with something?. Are there things at home一like a computer or other tools (工具) 一that I can use to earn money?() 1. Children can have full-time jobs at the age of in the USA.   A. 16   B. 14   C. 13   D. 10() 2. If you are 15 years old,you can work every day in the summer holiday.   A. about 4 hours   B. about 5 hours   C. about 6 hours   D. 30 hours() 3. Reisa makes money by .   A. cleaning up other people's yards   B. drawing pictures for others   C. writing articles for children's magazines   D. knitting dog sweaters and selling them to her neighbours() 4. You need to think about something when you wantto make money. Which is NOT mentioned (被提妾!J) ?   A. Skills and time. B. Parents’ help. C. People's needs. D. Tools.() 5. The passage tells us that .   A. teachers won’t let children earn their own money   B. all the children can earn their own money in the USA   C. children can also learn some important skills when they learn to earn money   D. if children try to earn money,they won’t have enough time to study