题干

保证食品安全、保持营养均衡,是保障人体健康的基础.

①人体所需的元素从食物中摄取不足时,可通过食品添加剂和保健药剂以补充.如制成补钙、补锌的保健药剂或制成加碘食盐等,来增加对这些元素的摄入量.从上面提到的补钙剂、补锌剂和加碘食盐中的钙、锌、碘是指____(填选项字母).

A.单质 B.原子 C.元素 D.离子

②被霉菌污染的粮食会产生黄曲霉素(C17H12O6),人类的特殊基因在黄曲霉素作用下会发生突变,继而诱发癌症.黄曲霉素属于____(填“无机物”或“有机物”),

③由于化学物质使用不当,给人印象不佳的化学名词越来越多:苏丹红、三聚氰胺、….下列做法不会危及人体健康的是____(填字母).

A.用甲醛浸泡海鲜产品 B.用霉变花生压榨食用油

C.用小苏打做糕点的疏松剂 D.用工业盐亚硝酸钠腌渍鱼肉

④碳酸氢钠是常用的疏松剂,它们在加热条件下产生气体,使食品变得疏松.请写出相关反应的化学方程式____.

上一题 下一题 0.0难度 选择题 更新时间:2019-10-03 11:45:40

答案(点此获取答案解析)

C,\u6709\u673a\u7269,C,2NaHCO3 \u52a0\u70ed_

同类题2

从A-F中选择其中五个填入短文中相应空格处,其中一个选项是多余。

Giving directions in different places

    If you ask people of different countries "Could you tell me the way to the post office?", you will get different answers.

    In Japan, people use landmarks instead of street names. For example, the Japanese will say to travelers, "Go straight down to the corner. ____ The post office is across from the bus stop."

    In Kansas, America, there are no towns or buildings within miles. So instead of landmarks, people will tell you directions and distance. For example, people will say, "Go north two miles ____".

    People in Greece sometimes do not even try to give directions. They will often say, "Follow me." ____ Sometimes if a person doesn't know the answer to your question, he or she, like a New Yorker, might say, "Sorry, I have no idea." But in Yucatan, Mexico, no one answers "I don't know". ____ They usually give an answer, but often a wrong one. A visitor can often get lost in Yucatan!

____ You might not understand a person's words, but maybe you can understand his or her body language. He or she will usually point to the correct direction. Go on in that direction and you may find the post office!

A. Turn east, and then go another mile.

B. But one thing will help you everywhere.

C. People there think "I don't know." is not polite.

D. Turn left at a big hotel and go past a fruit market.

E. Then he or she will take you through the streets of the city to the post office.

F. Sorry, I don't know, I'm a stranger here.