问题 问答题 简答题

试述还原。偶氮分光光度法测定水中硝基苯类化合物的原理。

答案

参考答案:

在含硫酸铜的酸性溶液中,由锌粉反应产生的初生态氢将硝基苯还原成苯胺,经重氮偶合反应生成紫红色染料,进行比色测定。

完形填空

请阅读下面短文。根据短文内容从下面方框内的七个选项中,选择五个还原到文中,短文意思通顺、结构完整,并在答题卷上讲其序号涂黑。(每小题2分)

小题1: I like it because although it’s hard work, every day is different! It all depends on what is wrong with the animals that come in.

At my clinic(诊所), I work long days on Mondays, Wednesdays and Fridays, and short days on Tuesdays, Thursdays and Saturdays. Sunday is my day off so I can spend some time with my family.

 小题2: My clerk opens the door, turns on some music, and makes everyone a cup of tea or coffee. My assistant cleans and feeds the animals. The phones start to ring and people make appointments. This is a very busy time of day!

At 9 am, pet owners start to arrive with their sick pets. Appointments take up the whole morning. 小题3: I don’t examine(检查)any new sick animals. I use these two hours to have lunch and do all my paperwork.

At 2 pm. I start to see sick animals again. At 5 pm, three students from a local school who love animals arrive to help out. 小题4: I am always happy to see their smiling faces!

From 5 pm to 7pm, I continue to see sick animals. Then, at 7 pm, we close our doors and the clean-up begins! We tidy the clinic, and feed and clean the animals. Of course,we also stroke(轻抚)them and give them hugs! Then, we turn off the lights and go home. 小题5: 

I’m very happy being a vet, though unexpected things sometimes happen!

 

单项选择题