题目

下列图象能正确反映对应操作中各量变化关系的是（ ） A．将生锈的铁钉放入足量的稀盐酸中 B．向两份完全相同的稀硫酸中分别加入镁粉、锌粉 C．水的电解 D．向过氧化氢的水溶液中加入二氧化锰制氧气 答案：A 【详解】 A、铁锈的成分是氧化铁，氧化铁会先和盐酸反应生成氯化铁和水，然后过量的盐酸会和铁反应生成氯化亚铁和氢气，所以反应一段时间之后会有氢气生成，当铁反应完之后不再产生氢气，正确；B、向两份完全相同的稀硫酸中分别加入镁粉、锌粉，应该产生相同的氢气，错误；C、电解水产生 Many teenagers feel that the most important people in their lives are their friends．They believe that their family members don’t know them as well as their friends do．In large families．it is quite often for brothers and sisters to fight with each other and then they can only go to their friends for ideas．It is very important for teenagers to have one good friend or a group of friends． Even when they are not with their friends，they usually spend a lot of time talking among themselves on the phone．This communication (交流) is very important in children’s growing up，because friends can discuss something．These things are difficult to say to their family members．However, parents often try to choose their children’s friends for them．Some parents often may even stop their children from meeting their friends．Have you ever thought of the following questions? Who choose your friends? Do you choose your friends or your friends choose you? Have you got a good friend your parents don’t like? Your answers are welcome．1.Many teenagers think that can understand them better．A．friends B．brothers C．sisters D．parents2. is very important to teenagers．A．To make friends B．CommunicationC．To stop meeting friends D．Both A and B3.When teenagers have something difficult to say to their parents，they usually ．A．stay alone at homeB．fight with their parentsC．discuss them with their friendsD．go to their brothers and sisters for help．4.The sentence” your answers are welcome．”Means“ ”．A．You are welcome to discuss the questions with usB．We’ve got no idea, so your answers are welcome with usC．Your answers are always rightD．You can give us all the right answers5.Which of the following is the writer’s attitude (态度)?A．Parents should choose friends for their children．B．Children should choose everything they like．C．Parents should understand their children better．D．Teenagers should only go to their friends for help．