题干

我国已经全面进入高铁时代,为适应提速要求,需要把短轨焊接成长轨,常用如下反应 XAl + Fe2O3 高温__ XFe + Al2O3 焊接铁轨,该反应发生后不需要持续加热就可保持高温继续进行,方便野外操作,下列说法错误的是(   )

A:该反应方程式中的X 为3   

B:Al2O3 属于氧化物

C:该反应为置换反应   

D:该反应会放出大量的热

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答案(点此获取答案解析)

A

同类题5

书面表达

假如你是某英语杂志社编辑王林,根据下面中学生小明的来信,给他写一封回信,解答他的困惑。

要求:1. 观点鲜明,结构合理,内容连贯;

2. 词数80左右,信的开头和落款已给出,不计入总词数。

Dear editor,

   Nowadays, many junior high school students are completely getting relaxed from busy study after graduation,  so what they would like to do most is to throw books away, hang out with friends at daytime and stay up late at night playing computer games or watching TV. What's your opinion about this? I'm looking forward to your reply.

                                                                                                                                                                                                      Yours sincerely

         Xiaoming

Dear Xiaoming,

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Yours,

Wang Lin