人教版（新课程标准）高中英语必修2 Unit 4 Wildlife protection同步练习3

    Elephants are able to know the difference between a man and a woman, and can tell an adult (成年人) from a child—all from the sound of a human voice. This is according to a study in which researchers played voice recordings to wild African elephants.

    The animals showed more fear when they heard the voices of adult Masai men. Usually Masai people hunt elephants, and this suggests that animals have grown to listen for and avoid them.

    Prof. Karen McComb and Dr Graeme Shannon from the University of Sussex led the study. They explained that in former research they had used similar experiments to show that elephants could tell—from the sound of a lion—whether the animal was a female (雌性) or a more dangerous male (雄性).

    Prof. McComb wanted to find out if the animals used their very sharp sense of hearing to recognize danger from humans.

    The scientists recorded Masai men, women and children saying, in their own language, “Look, look over there, a group of elephants are coming.” They also recorded Kamba men saying this phrase.

    Masai people often come across elephants, which can result in violent (暴力的) hunting. Kamba people, however, mainly feed on agriculture, which does not generally bring them into violent touch with the animals.

    When the team played recordings of these different voices through a hidden speaker, they found that elephant family groups showed more fear in response to the voice of a Masai man, than to a Kamba man's voice. And the adult male Masai voices caused far more violent response than the voices of women or boys.

    We find different kinds of animals in the world. Some animals, such as tigers and lions, live in big forests and they are called 1 animals. Some others like sheep and dogs are2by men and they are called domestic animals (家养动物). These animals are very different from one another, but we can 3 them into big groups: those that eat other animals and those that eat grass and leaves. Animals like the4belong to the first group.

    Animals are 5 great use to human beings. Men6 wild animals for their 7 and meat. Domestic animals are 8 more important to men. Without them, life will be 9People make use of animals in many 10.

    Cows and pigs are useful to men's 11. They give 80% of the12men eat every year. Skin of some animals can be 13 into expensive overcoats and shoes, which are warm and comfortable and 14 a long time. They are very welcome in15countries.

    Wool, which is now one of the most important materials (原料) for textile (纺织)16 comes from some certain17 From cows, we get milk. And we shouldn't 18that some domestic animals are kept for transport. Many people 19ride horses. Arabs ride on camels that travel in deserts for days without drinking. In some places animals are still used to plough (犁地) the field. It is20 that men just can't live without these animals.