根据你的生活经验和所学的化学知识判断，下列做法正确的是（）_爱下问搜题

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问题选择题

根据你的生活经验和所学的化学知识判断，下列做法正确的是（）

A．在食品袋里充入氧气延长食品的保质期

B．被蚊虫叮咬后，可涂一些含有NH₃·H₂O的药水

C．为了使养分还田而将植物秸秆焚烧处理

D．常用钢丝球擦洗铝壶可以使其光亮洁净和更耐用

答案

答案：B

A、在食品袋里充入氧气会缩短食品的保质期，因为氧气性质活泼，此项错误．

B、被蚊虫叮咬后，可涂一些含NH₃•H₂O的药水，正确，因为氨水呈碱性，和蚊虫叮咬的酸性物质中和．

C、秸秆焚烧会成资源浪费，还会造成空气污染，故此项错误；

D、铝壶表面有一层致密的氧化物薄膜，对铝壶起到保护作用．如果用钢丝球擦洗，可能把氧化物薄膜擦去，所以不能用钢丝球洗刷铝制炊具，此项错误。

故选B。

完形填空

I will never forget the two impressive things that happened last winter. One of my classmates and I were 36 our project work late at night on my university's campus far from home. Since there was 37 in the forecast, I had worn a winter 38 to school that day with a raincoat in my bag.
Throughout

our work on the project, I could 39 that my friend was tired from a very long day working. As we stepped outside to begin the 40 walk home, I 41 she was shivering(颤抖). The temperature had dropped to the low thirties (Fahrenheit) and she 42 had a swea

ter on. I 43 offered her my warm jacket. She accepted it and asked me what I 44 wear then. I told her I had another one and pretended that my 45 was a jacket. She said later that she 46 the next morning and the first thing on her mind was feeling moved about my 47 of the jacket.
Coincidentally(碰巧), the next day I went to an open-air play and I was freezing 48 I didn’t expect it to be so 49 . A person who I hardly 50 insisted that I wear his jacket. I was 51 touched by this warm gesture. He was so matter-of-fact(讲究实际的) about me 52 his coat, too: he simply took it off and handed it to me telling me that I should 53 it. I used to think that this vast universe was a cold 54 . It turns out that even when the temperature drops low, the people never 55 to warm each other's hearts.

B．immediately

A．environment

单项选择题

解吸剂冷却流程开通时应注意（）

A.应用小流量，开通过程要慢，防止发生液击。

B.投用冷却器

C.确认并开通冷却器的出口物料流程

D.以上全是