Today, we consider zero as a common number. Few of us know zero has an unusual history. Yes, zero is, in fact, different from the other numbers.
At first, there were only the numbers one to nine. Zero started to be seen in India about 2,000 years ago. Many other ancient cultures had been marking nothingness. However, the ancient Indians were the first to consider nothingness as a number.
Little by little, communication around the world became more often. Finally, zero was brought out of India. It was accepted as an Arabic (阿拉伯的) number. During the 13th century, Arabic numbers were introduced to the West. However, people in the West had been used to using Roman numbers (I, V, X, etc.). Arabic numbers were not popular. This was especially true for zero. Since there is no zero in Roman numbers, people found it hard to accept the new number. It was quite easy for dishonest business people to turn a “0” into “6” or a “9”. Some people, therefore, believed zero would lead to much trouble. Zero was also seen as an unlucky number. That’s because it is close to negative numbers—the idea of having debts (债务). People in Florence even weren’t allowed to use zero citywide.
It was not until the 15th century that zero and the other Arabic numbers were fully accepted. Business people played an important role. Just think about doing calculations (计算) using Roman numbers. You can hardly do any trade, can you?
The | ||
Introduction | Zero is not the | |
| Different of zero | 2000 years ago | Before zero |
During the 13th century | Arabic numbers were It was not People believed zero would Zero was not seen as a | |
| Until the 15th century | People | |
相似题推荐
On the Tower at Youzhou
Where are the great men of the past?
And where are those of future years?
The sky and earth forever last;
Here and now I alone shed (流) tears.
Traveling not only opens our eyes but also gives us a chance to think and express our feelings. On the Tower at Youzhou, written by Chen Ziang (661-702) in the Tang Dynasty, is an example.
Chen wrote this poem in 696. At that time, he was upset in his army career (生涯) under the rule of Empress Wu Zetian. He climbed to the top of Youzhou Tower and was amazed by the view of the earth and sky. He couldn’t help wondering where the great men of the past and future are.
Compared to the universe, the poet felt that people are small and unimportant. What lasts forever is the vast (广阔的) earth and sky. Nobody can be free from death. Even so, Chen still wanted to serve his country and people in his short life. But the rulers didn’t see his talents, so Chen felt sad and shed tears alone.
With the sincere (真挚的) feelings that fit the setting, Chen created a moving, sad scene in the poem. It is sad but not discouraging (令人气馁的). His language is simple but carries deep meaning. That’s why the poem is still popular now.
1. What can we get through traveling according to the passage?2. Where did Chen see the amazing view of the earth and sky?
3. Why did Chen cry alone?
4. According to Chen, are people important compared to the universe?
5. What does the writer think of the language in the poem?
【推荐2】Red and yellow can facilitate(促进) learning
Students usually prefer to study in environments with light colors. They say the light colors make them feel more relaxed, but researchers have found the opposite works better.
According to a study from Curtin University in Australia, the students’ concentration(专注) levels are higher when they are in environments with bright colors. In the study, the students were asked to read a passage and answer questions in rooms with different colors. They were light and bright blue, red and yellow. The students’ reading comprehension(阅读理解) scores were higher in the bright red and yellow rooms.
Aseel Al-Ayash, one of the researchers in the study, said, “Bright colors can support students’ learning performance by positively(积极地) affecting physical and mental states. If the reading tasks are difficult, the bright colour conditions may increase excitement to the best levels.” Several past studies have shown that the colors red and yellow are more stimulating(有刺激作用的) than blue and green.
However, two-thirds of the students in the study believed that bright red wasn’t a suitable colour for a study room. They connected the colour with depression(沮丧), discomfort, anger, danger and things like that. But they could improve their learning results by using the colour—so perhaps a bit of discomfort is what they need.
Maybe in the future, red and yellow will be the popular colors of study areas because of the study.
1. Students usually prefer to2. The students’ concentration levels are
3. If
4. Several past studies thought that the colors
5. Maybe in the future,
Do you love street food? I’m sure you do! What makes the food sweet? Sugar, of course! Do you know anything about sugar? Most sugar comes from sugar cane (甘蔗). This kind of plant is very tall.
How do we make sugar from sugar cane?
First, farmers cut the top of the plant and put part of the plant in the earth. This will grow into more sugar cane.
Next, workers make the sugar cane into big machines. One machine washes the cane. One machine cuts and turns the cane over and over. And one machine gets the sweet juice from the cane.
Then, workers make the juice hot and it becomes thick (浓稠的). The thick juice is called syrup (糖浆). Workers put the syrup into the crystallization tank (结晶罐). It turns to crystals (晶体). We need one more machine to dry the crystals. Now we have sugar.
Sugar can be brown or white. It can also be in different sizes. Then the sugar can go to the sweet factory (工厂). There workers use it to make sweets.
根据短文内容，回答下列问题。（每小题答案不超过六个单词）
1. Where do most sugar come from?
2. What is the thick juice called?
3. How many machines do workers need to make sugar?
4. Is sugar in the same size?
5. Why do people send the sugar to the sweet factory?
On 4th of February, 2018, there was an earthquake that happened in Taiwan. It was a level 6.4 earthquake. As we know, earthquake is very dangerous and terrible. But do you know what to do during and after an earthquake? Here is some advice for you.
Before an earthquake. It is necessary to prepare yourself and your family. All family members should know the way to turn off gas, water and electricity and know useful telephone numbers. Never put heavy things over beds.
During an earthquake. It’s important for each of you to stay calm. If you are indoors, quickly move to a safe place in the room such as under a strong desk or a strong table. It can protect yourself from falling things. Stay away from windows, large mirrors, heavy things and so on. If you are cooking, turn off the gas.
If you are outdoors, move to an open area like a playground. Move away from buildings, bridges or trees. If you are driving, stop the car as soon as you can. Stay in your car.
After an earthquake. Once the shaking stops, do not run out of the building at once. It’s better to wait and leave when it is safe.
Check around you and help people in trouble. If your building is badly broken, you should leave it. If you smell or hear gas, get the people around outside and open windows and doors. If you can do it safely, turn off the gas. Report it to the gas company.
| Some useful | |
| Before an earthquake | ￭ Make sure that everyone in the family should know ￭ Remember some useful telephone numbers. ￭ Don’t put |
| Stay ￭ If you are ￭ If you are outdoors, it is important for you to move to an open area right away. ￭ If you are driving, you should remember to stop your car as soon as | |
| After an earthquake | Don’t leave ￭ Check around you and be helpful to the people in trouble. ￭ Leave your badly broken building as soon as possible. ￭ Help people inside to find their way |
Do you like winter? It’s a cold season of a year. Here are some things everyone should know about winter.
Winter weather
In winter, the temperature (温度) is low. And you can see snow sometimes. When the temperature is below zero, water freezes (结冰).
Winter fun
After a heavy snowfall, children play in the snow. They make snowmen and have snowball fights. People also enjoy skiing and skating in winter.
Winter dangers (危险)
The cold weather can also be dangerous. People fall down on the ice and cars can also have traffic accidents. Some people also catch a cold when they stay outside.
Keeping warm
Because winter is so cold, people have to find ways to keep warm. People wear heavy coats, scarfs for their necks, gloves for their hands, and boots on their feet.
1—2题为完成句子；3题为简略回答问题；4题找出并写下全文的主题句；5题将为文中划线句子译成汉语。
1. In winter, the temperature is
2. After a heavy snowfall, children can
3. Why do people have to find ways to keep warm in winter?
4.
5.
Is Chinese your favourite subject? Many foreigners learn Chinese now.
In Russia (俄罗斯), middle school students can learn Chinese at school. Students have one or two Chinese lessons a week. In 2007, about 17,000 people in Russia learn Chinese. And now, the number is 56,000.
Sergey is one of them. He is a thirteen-year-old student. He likes Chinese very much. Chinese is difficult for him to learn. Luckily, he has a good Chinese teacher—his mother. His mother is a Chinese. Sergey likes Monday, because he has Chinese on Monday. His Chinese teacher at school is also fun.
1. How many Chinese lessons a week do students have in Russia?2. How old is Sergey?
3. Is Sergey’s mother a Chinese?
4. Why does Sergey like Monday?
