问题 问答题

某版本教材中通过以下五个步骤对馒头在口腔中的变化作实验探究,写出相关的教学目标、教学重难点及其相关的教学准备。(1)假设:馒头中的淀粉在口腔中会变成麦芽糖(2)实验材料:两个相等的容器、水、唾液、碘酒(3)试验计划:先在两个容器中加入同样等分的馒头,然后再分别在两个容器中加入同样等分的水和唾液,将温度保持在37度左右。几分钟后再分别在两个容器中加入同样等分的碘酒。(4)结果:加唾液的没有变蓝,而加水的变蓝了。(5)结论:馒头中的淀粉在口腔中变成了麦芽糖。

答案

参考答案:

(1)教学目标知识与技能目标:①描述馒头在口腔中的变化;②说出淀粉在唾液淀粉酶作用下变为麦芽糖。过程与方法目标:能设计对照实验,探究唾液、舌、牙齿在“馒头在口腔中的变化”中的作用。情感态度与价值观目标:在小组合作完成“探究馒头在口腔中的变化”中,积极主动参与,对探究方案的设计及实施作出自己的贡献。

(2)教学重难点教学重点:探究唾液、舌、牙齿在“馒头在口腔中发生变化”中的作用。教学难点:确定实验变量,设计实验过程。

(3)课前准备教学演示文稿,消化系统结构图片,试管若干,试管架,消毒口杯,玻璃棒,小刀,蒸馏水,碘液,馒头等。

单项选择题 A1/A2型题
阅读理解

     People are overweight for many reasons, the most important one of which is that they eat the wrong

foods, get the wrong types of calories per meal, and they also eat meals at the wrong time each day.

Food is more powerful than any weight loss pill, because the food that you eat can either make you thin

or fat. This is true because your body is like an engine, and it only needs certain foods at certain intervals(间隔)each day.

     Low-calorie Diets Do Not Work

The reason people cannot lose weight by starving themselves is that their metabolism(新陈代谢)will

detect any major drop in calories and it will then adjust(调整)itself by burning fewer calories each day.

That is the reason why you can eat 1,000 calories per day and not lose any weight, while your friends

can eat 2,500 calories per day and not gain any weight.

     Low-fat Diets Do Not Work

     Many people in today's society are buying mostly low- fat or non-fat food at the grocery store.

Everybody knows how much fat is inside the food they buy. However, people are getting fatter than ever

before by doing this. They are not losing weight by changing to this low-fat lifestyle.                  

     Losing weight has nothing to do with these things. One of the most important things you can do to

control your weight is to eat the proper foods, such as fruit and vegetables, eat them at the right time, and

exercise every day. If people make this a habit, they will lose weight.

1. What is the main reason why people are overweight according to the author?

A. They eat the wrong foods at the wrong time.

B. They eat food with lots of calories.

C. They don't take any weight loss pills.

D. They burn many calories every day.

2. The article is written in order to _______.

A. tell readers not to buy low-fat or non-fat food

B. tell readers how to lose weight

C. tell readers about an important scientific discovery

D. call on people to lose weight and stay healthy

3. To realize the aim of your weight loss plan, you should ________.

a. do exercise every day      

b. eat meals at the right time

c. eat fruits and vegetables    

d. eat low-fat or sweet food

e. eat the proper foods at each meal

A. a, b, c, d              

B. a, b, d, e    

C. a, c, d, e              

D. a, b, c, e