成瘾性

阅读理解。

     MSG (monosodium glutamate) is a food additive (食品添加剂), which has been widely used by many

food factories all over the world since it appeared first in Japan in 1909.

     MSG is a substance that is added to some food to improve its original (原先的) taste and colour. It is

used in foods around the world such as cakes, bread, frozen meats, fish and vegetables. In the beginning,

people thought MSG was safe just like salt and sugar. However, in 1968 some people reported they seemed

to have bad reactions (反应) to MSG after having had a meal at a restaurant. They included headaches and

quick heartbeat (心跳). It was also reported that MSG excited a person's brain and caused his death in Japan.

Scientists think that MSG may lead to many neurological disorders (神经紊乱). In mice studies done by a

university, the evidence showed the mice didn't want to eat the food including MSG.

     Today many food companies"hide" MSG on food labels (标签) by using different names. If you see

"natural flavorings", "hydrolyzed protein" and "spices" in a food label, you are probably seeing a hidden way

to "report" MSG in a food label. Every time we have a meal in a restaurant, we always feel the food very

delicious to taste, but sometimes it is dangerous for our health because some poisonous food additives have

been added to the food.

     To protect people's health, our governments, from central to local, are taking actions to stop factories

producing poisonous food additives.

1. Monosodium Glutamate is _______.

A. a food

B. an additive

C. a factory

D. a country

2. MSG is often used in _______.

A. frozen meats

B. cups

C. clothes

D. book covers

3. The examples in the second paragraph tell us ________.

A. the food including MSG is delicious

B. people like to eat in a restaurant

C. mice like eating the food including MSG

D. MSG is not safe sometimes

4. If you see "natural flavorings", "hydrolyzed protein" and "spices" in a food label, you will know—________.

A. you must eat the food in a hidden way

B. the food label must be hidden

C. MSG is probably added to the food

D. you must report the food to your parents

5. The underlined word "substance" in the article means __________.

A. colour

B. material

C. taste

D. food

火灾事故的防范原则包括预防、（）、灭火、和疏散四个方面

A.限制

B.报告

C.检察

拍摄方位中的（）是指摄像机对着被摄物的正面拍摄，将主体常处于画面的中心，易于表现事物的基本特征。

A.正拍

B.斜侧拍

C.侧拍

D.反拍

卡塞格伦天线是一种（）的微波天线，它包括一个抛物面形的主反射镜和一个双曲面形的副反射镜。

信息传输风险是指进行网上交易时，因传输的信息失真或者信息被非法地（），而导致网上交易的不必要损失。

A.窃取

B.篡改

C.丢失

D.以上三种都有可能