搜题请搜索小程序“爱下问搜题”
问题 选择题

将铁粉和硫粉混合无明显现象，加热，待反应一发生就立刻停止加热，反应可以持续进行，直至完全生成新物质硫化亚铁。该现象说明了

A．该反应是分解反应

B．该反应是放热反应

C．该反应生成物的化学式为 Fe2S3

D．生成物硫化亚铁的总能量高于反应物铁粉和硫粉的总能量

答案

答案：B

题目分析：停止加热时反应仍能继续进行，说明反应放热；而反应的产物为FeS。

写作题

写作。

         一年一度的班长竞选又开始了.下面是Jack的竞选海报,请你根据海报内容决定是否选举他作为班长,并陈述

你的理由.要求:语句通顺；语法正确；60词左右.

                                                          Vote for Jack

     If I am class president, I will love the job, care about my classmates, and serve them better.

     If I am class president, I will be glad to help any student in our class. I will try my best to help him or her with his

or her studies or life.

     If I am class president, I will help teachers keep the school rules and solve some problems in class.

     If I am class president, I would like to hold some interesting after-class activities for my classmates on weekends.

     I hope everybody can vote for me!

_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
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单项选择题

修剃胡须时，由于较粗硬，故刀锋的倾斜角度可稍大些，这样修剃（）。

A.切断力强，且不易刮破皮肤

B.保护皮肤，且能修剃干净

C.即能剃净又能较舒适

D.没有不适感觉又能剃净
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