题目

向某稀HNO3和Fe(NO3)3的混合溶液中逐渐加入铁粉，产生无色气体．该气体遇空气变红棕色，溶液中Fe2+浓度和加入 Fe粉的物质的量之间的关系如图所示：则稀溶液中HNO3和Fe(NO3)3的物质的量浓度之比为    A．2：1       B．1：1       C．4：1      D．3：1 答案：C错解分析:学生未掌握解决图像题目的要领，不能从图像中提取出有效的信息。读图时一要注意图像的拐折点的含义，二要注意坐标对应的数据。从中找出恰好反应点。解题指导:从曲线可知，当加入l mol Fe时,n(Fe2+)=0，说明Fe和稀HNO3反应生成Fe3+．由Fe+4HN0(稀)==Fe(N03)3+NO↑+2H20。即lmol Fe消耗4 mol HN03，由Fe+2Fe3 阅读理解 　　A year ago, I paid no attention to English idioms, though my teacher emphasized the importance again and again．But soon, the importance of English idioms was shown in an amusing experience． 　　One day, I happened to meet an Englishman on the road, and soon we began to talk．As I was talking about how I was studying English, the foreigner seemed to be astonished gently shaking his head, shrugging his shoulders, saying,“You don't say!”“You don't say!”I was puzzled．I thought, perhaps this is not an appropriate topic．“Well, I'd better change the topic．”So I said to him,“well, shall we talk about the Great Wall?”By the way, have you ever been there?“Certainly, everyone back home will laugh at me if I leave China without seeing it．It was magnificent(壮丽的)．”He was deep in thought when I began to talk like a tourist guide,“The Great Wall is one of the wonders in the world．We are proud of it．”Soon I was interrupted again by his order“You don't say!”I couldn't help asking．I said,“Didn't you say you don't say?”Hearing this, the Englishman laughed to tears．He began to explain,“You don't say actually means really?It is an expression of surprise．Perhaps you don't pay attention to English idioms．”Only then did I make a fool of myself．Since then I have been more careful with idiomatic expression． (1) A year ago, I paid no attention to English idioms because ________． [　　] A． English idioms were too difficult to master B． I cared little about the teacher's instruction C． my teacher didn't emphasize the importance D． I had no interest in English learning (2) When I first heard“You don't say!”I thought ________． [　　] A． the Englishman was not interested in my English B． the Englishman was only interested in the Great Wall． C． I had talked too much D． I had to stop talking at once (3) Which of the following is true? [　　] A． The Englishman was leaving China without seeing the Great Wall． B． The Englishman wanted to see the Great Wall after I talked about it． C． The Englishman wanted me to act as his guide． D． The Englishman visited the Great Wall and thought it worth visiting (4) After the Englishman explained the idiom, ________． [　　] A． the Englishman made me a fool B． the Englishman made a fool of himself C． I felt very silly D． I felt proud of my understanding