问题 选择题

某化学反应的微观示意图如图所示,则下列说法正确的是(  )

A.反应前后分子种类、数目均不变

B.该反应属于复分解反应

C.该反应中,反应物的质量比是1︰1︰1

D.该反应的产物均为化合物

答案

答案:D

题目分析 反应前后物质的种类会发生改变,即有新物质产生,所以分子种类肯定改变,而分子的数目可能改变,此反应不属于复分解反应,因为反应物中有一种是单质,反应物为两种,不可能是1︰1︰1,应该是2:1,生成的产物都是由不同元素构成的,均为化合物。

改错题

短文改错。

     假定英语课上老师要求同桌之间交换修改作文,请你修改你同桌写的以下作文。

文中共有10处语言错误,每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加:在缺词处加一个漏字符号(^)。并在其下面写出该加的词。

删除:把多余的词用斜线(/)划掉。

修改:在错的词下划一横线,并在该词下面写出修改后的词。

注意:1. 每处错误及其修改均仅限一词;

          2. 只允许修改10处,多者(从第11处起)不记分。

Dear Ms Smith,

     I am secretary of the City Student Union (CSU). We were organizing an art exhibition for high school

students in city. This will be held on the 9th of July in the Exhibition Hall of Beihai. More than 1000 paining

will be on show, but high school students from all the eight districts will come to the event. As you are very

popularly with us Chinese high school students, we'd like to invite for you to the exhibition. We would be

grateful when you could join them that day. Looking forward to hear from you soon.

                                                                                                                                           Yours,

                                                                                                                                           Li Ming

_______________________________________________________________________________________

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