题型:阅读选择 题类:常考题 难易度:普通
2016年浙江省温州市中考英语试卷
Harmful microbes like bacterias, viruses and other germs are pathogens. They may enter your bodies and make you ill. The immune system is the body's defence system that protects you from illness and disease caused by the pathogens.
The immune system is made up of non﹣specialized defences such as skin, tears and the acidic juice produced by the stomach, keeping you from the pathogens. It also has some highly specialized defences, which are different kinds of immune cells, grouped into phagocytes and lymphocytes. Phagocytes are a type of white blood cell. They are swimming around in your blood stream, always on the lookout for antigens﹣the pathogens that have entered your bodies. Whenever they see one, their will eat it. However, some antigens are hard to find and kill. Then lymphocytes, which are also white blood cells and the main types are B cells, T helper cells and T killer cells, Will be the killers of the sneaky antigens.
B cells, T helper and T killer cells work together to find and kill these antigens. B cells produce substances, called antibodies, which stick to the antigen. When that happens, it will tell the T helper cells to come over and either: 1. help the B cells kill the antigen, or 2. call the phagocytes or T killer cells to move in for the kill. Once a B cell or a T cell attacks an antigen, they create cells to "remember" it. Those "memory cells" hang out in your blood if they see the same antigen again, they quickly recognize, it so your immune system can act faster at killing it.
The immune system is more powerful than you probably imagine. Scientists from the University of Pennsylvania recently took immune cells from three patients with leukemia, then genetically changed them into "serial Keller "cells to attack cancer cells. The study was small but the results were groundbreaking. The modified immune cells increased at least 1, 000 times in the body and killed all the cancer cells. Therefore, more "memory cells" were created.
The immune system can be developed. Eating lean protein food (beef, beans )and food rich in vitamins A, C, and E(sweet potatoes, carrots ), taking a 30﹣minute walk every day and reducing your stress levels, etc. will help you achieve it.
Our life will be different from nowadays with robots appearing in our homes. So what will the future be like? Here are some students' ideas.
I expect to live in a more beautiful and cleaner city. The street will be cleaned by the robots once a day. —Ben |
There will be more kinds of food to choose from and the food will be more delicious. The robots can make food for us。 —Karen |
We do not have to spend much time on heavy work because robots will take up most of our work, such as washing the clothes. So we will have more vacations. We can take a vacation on the moon. We will not live on the earth but on the moon or other planets. —Mark |
I expect that most families will have their own planes made by their robots, and travel will become more convenient. The plane is faster than any other transportation(交通工具). —Sue |
I hope robots can make clothes for us. The clothes could change their sizes and colors by themselves. —Sam |
What will man be like in the future-in 5. 000 or even 50, 000 years from now?We can only make a guess, of course, but we can be sure that he will be different from what he is today. For man is slowly changing all the time. Now look at the chart below, and you'll find some differences.
Body part |
Changes |
Reasons |
Height |
Grow taller |
About 3 inches taller than 500 years ago |
Head |
Larger |
Man uses brains more and more |
Eyes |
Grow stronger |
|
Arms and legs |
Grow weaker |
Used less |
Fingers |
Grow more sensitive |
Used a great deal in modern life |
Hair |
Disappear |
Does not serve a useful purpose any longer |
Perhaps all this gives the impression that future man will not be a very attractive creature(生物) to look at!This may well be true. All the same, in spite of all these changes, future man will still have a lot in common with us. He will still be a human being, with thoughts and emotions(情感) similar to our owns.
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