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问题 填空题

某化学课外活动小组，对钢铁制品的锈蚀的条件进行如下探究，

设计了如图所示的实验，据此回答下列问题：

（1）一周后，观察到编号为______的试管中的铁钉锈蚀严重．

（2）常温下，铁生锈是铁跟______和______等物质相互作用的结果，铁锈的主要成分是______（化学式表示）．

（3）人们通常用稀盐酸或（稀硫酸）除去铁器表面的锈，其原理可用化学方程式表示为（写出其中一个即可）______．

（4）如何防止家庭中常用的铁制品生锈，简单易行的方法有（列举一种）______．

答案

（1）B中的铁钉与氧气和水充分接触，容易生锈．故填：B．

（2）常温下，铁生锈是铁跟氧气和水等物质相互作用的结果，铁锈的主要成分是氧化铁．故填：O2；H2O；Fe2O3．

（3）稀盐酸和氧化铁反应生成氯化铁和水，反应的化学方程式为：6HCl+Fe2O3=2FeCl3+3H2O．

（4）在铁制品上涂上一层油漆可以防止铁制品生锈．故填：在铁制品上涂上一层油漆．

单项选择题

胃幽门部粘膜病变可导致哪种维生素缺乏()

A．维生素E

B．维生素B6

C．维生素B12

D．维生素C

E．维生素K
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填空题

阅读短文，根据短文内容，从短文后的五个选项中选出能填入空白处的最佳选项。选项中有一项为多余选项。

Note-taking is a skill that can help you do well in all your schoolwork. It can make you confident when you are studying. 小题1:____________________

If your teacher writes notes on the blackboard, that's great. You can copy them or write down the most important facts of all in class. 小题2:____________________ For example, some teachers may focus on (关注) lots of dates and facts in class, but they only write the important ones on the blackboard. Other teachers may not write anything down, but they may repeat them.

Don't try to write down every word in class, or you might miss some important points. Some students really learn better with the help of these notes. 小题3: ____________________ If your teacher speaks too fast and you can't follow what he is saying, you can ask him after class.

Comparing your notes with your classmates' can be good for your learning. 小题4:____________________

Note-taking also needs organization. Keep notes for each subject in one place, so that you can find everything easily when a test comes.

Good note-taking takes time. If you decide to recopy your notes every evening, you'll surely have less time to watch TV. But you'll save time in the coming test.

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