题型:阅读选择 题类: 难易度:困难
【盐仓24秋】外研版(2024)英语九年级上册B本Module 12 Save our world Unit 2 第 2 课时
Have you ever wondered how many ants there are on the earth? Scientists at the University of Hong Kong certainly have. In a new study, they estimated (估计) the number of the world's ants is about 20, 000, 000, 000, 000, 000(20 with 15 zeroes!
That means for every human, there are nearly 2. 5 million ants. If you put all the ants on a scale, they'd weigh more than all the wild birds and mammals (哺乳动物) on the earth.
How did they count such a big number? In the past, many scientists have counted ants in different areas. They collected fallen leaves and earth and dried them to force the ants to come out for counting. Based on 465 studies that cover the whole land, the new study made the estimation. According to Wang Runxi, one of the authors, the number and distribution(分布) of ants can be valuable to show the environmental changes.
"Ants play an important role in the ecosystem, " Wang told Science and Technology Daily. "They help loosen the soil, spread seeds, break down things and form a part of the food chain (食物链). They are everywhere on the earth except for the coldest places. "
"Compared with big animals, little ants are more sensitive (敏 感 的 ) to environmental changes, " Wang added. Most ants live in tropical (热带的) and subtropical(亚热带的) areas. But in recent years, ants have been moving toward the two poles because of global warming. Changes in forests, such as too many trees being cut down, also have influence on the number of ants, the study showed.
"Our global map of ants allows us to better understand and predict ants' responses to worrying environmental changes, " scientists wrote in the study.
Introduction | Li Qiu often begins on August 7-9.The leaves from the trees start to fall,so there is a famous saying of One leaf falls , autumn arrives.And it's also a reminder for farmers to gather crops.There is a saying: "If it rains on that day,a good harvest is expected. | |
Weather | Though Li Qiu shows the beginning of autumn,hot weather will not come to an end.This period of hot days after Li Qiu is called"Autumn Tiger".The temperature is even hotter than that in Da Shu.After 30 days,the weather turns cool gradually. | |
Traditions | Touching autumn:People can take all kinds of fruits in private gardens for free as they like,and the owners won't be angry. Fleshing out in autumn:People eat many different kinds of delicious food to put on weight. Eating red beans:It is believed that people should eat more red beans which will be good for health. |
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