题目内容
Land animals are believed ______ from sea animals.
A. to have developed B. to have been developed
C. having developed D. having been developed
A
解析:
略
The African elephant, the largest land animal remaining on the earth, is of great importance to African ecosystem(生态系统). Unlike other animals, the African elephant is to a great extent the builder of its environment. As a big plant-eater, it largely shapes the forest-and-savanna(大草原) surroundings in which it lives, therefore setting the terms of existence for millions of other animals that live in its habitat.
It is the elephant’s great desire for food that makes it a disturber of the environment and an important builder of its habitat. In its continuous search for the 300 pounds of plants it must have every day, it kills small trees and underbushes, and pulls branches off big trees. This results in numerous open spaces in both deep tropical forests and in the woodlands that cover part of the African savannas(热带草原). In these open spaces are numerous plants in various stages of growth that attract a variety of other plant-eaters.
Take the rain forests for example. In their natural state, the spreading branches overhead shut out sunlight and prevent the growth of plants on the forest floor. By pulling down trees and eating plants, elephants make open spaces, allowing new plants to grow on the forest floor. In such situations, the forests become suitable for large hoofed plant-eaters to move around and for small plant-eaters to get their food as well.
What worries scientists now is that the African elephant has become an endangered species. If the elephant disappears, scientists say, many other animals will also disappear from vast areas of forest and savanna, greatly changing and worsening the whole ecosystem.
【小题1】What is the passage mainly about?
| A．Disappearance of African elephants. |
| B．Forests and savannas as habitats for African elephants. |
| C．The effect of African elephants’ search for food. |
| D．The eating habit of African elephants. |
| A．Fixing the time. | B．Worsening the state. |
| C．Improving the quality. | D．Deciding the conditions. |
| A．The African elephant is the largest animal on the earth. |
| B．African elephants have 300 pounds of plants every day, including small trees and underbushes. |
| C．The African elephant is in a way the builder of the environment like other land animals. |
| D．If the African elephant disappears, the whole ecosystem won’t be affected. |
| A．showing the effect and then explaining the causes |
| B．pointing out similarities and differences |
| C．describing the changes in space order |
| D．giving examples |
Elephants have four distinct personalities that help their herd survive in the African bush, scientists have found.
With their grey skin, mournful eyes and slow heavy pace, you could be forgiven for thinking elephants are uniformly melancholy(忧郁的) creatures. But scientists have now discovered the largest living land animals have personalities to match their size.
In a new study of African elephants, researchers have identified four distinct characters that are common in a herd – the leaders, the gentle giants, the playful rogues(小淘气) and the reliable plodders (辛勤工作的人).
Each of the types has developed to help the giant mammals survive in their harsh environment and is almost unique in the animal kingdom, according to the scientists.
Professor Phyllis Lee and her colleague Cynthia Moss studied a herd of elephants in the Amboseli National Park in Kenya known as the EB family — famous for their matriarch Echo before she died in 2009.
Using data collected over 38 years of watching this group, the researchers analyzed them for 26 types of behavior and found four personality features tended to emerge.
The strongest personality to emerge was that of the leader. Unlike other animals, where leadership tends to be won by the most dominant and aggressive individual, the elephants instead respected intelligence and problem solving in their leader. Echo, the matriarch and oldest in the group, her daughter Enid, and Ella, the second oldest female, all emerged as leaders.
The playful elephants tended to be younger but were more curious and active. Eudora, a 40-year-old female in the herd, seemed to be the most playful, consistently showing this feature throughout her life while playfulness in some of the other elephants declined with age.
Gentle elephants, which included two 27-year-old females Eleanor and Eliot, touched and rubbed against others more than the others.
Those that were reliable tended to be those that were most consistent at making good decisions, helped to care for infants in the herd and were calm when faced with threats. Echo and her youngest daughter Ebony seemed to be the most reliable.
Professor Lee said that elephants with these features tended to be the most socially integrated in the group while those who tended to be less reliable and pushy were more likely to split from the herd.
【小题1】From the passage we get to know that ________.
| A．the researchers reached their conclusion by analyzing the data |
| B．the research centered on the 26 types of behavior of the matriarch |
| C．the scientists conducted the research by comparing elephants with other animals |
| D．professor Phyllis Lee and her colleague spent nearly 38 years tracking the herd |
| A．playfulness of an elephant will always decline with age |
| B．those elephants which are caring and wise are most reliable |
| C．each elephant can be matched with only one of the four personalities |
| D．once becoming a member of a herd, an elephant will never split from it |
| A．mother and daughter | B．two oldest females |
| C．the gentlest ones | D．leader and member |