A mating group consists of two females and one male.A．YB．NC．NG

7,000 miles each way between the Arctic and Baja, California. The grey whales spend the long summer days in their Arctic feeding grounds in the Bering Sea between Alaska and Russia. Unlike a fish, the whale is warm-blooded and must therefore maintain a relatively high internal body temperature. In the cold Arctic waters the grey whale is protected by an outer layer of blubber which averages six inches in thickness. Other whales such as the Greenland Night whale have been found with a two-foot thick layer of blubber covering their bodies.

2. During these summer months, in the Arctic the grey whales fatten themselves by consuming enormous quantities of small shrimp-like animals called amphipods. Recent observations of a young grey whale, Gigi Ⅱ, held in captivity at Sea World in San Diego during 1971 and 1972, suggest that the grey whale feeds by sweeping its enormous head over the bottom. The amphipods on which it feeds are either stirred off the bottom or leap off the bottom to escape. These animals and the surrounding water are sucked into the whale&39;s mouth. As the water is expelled from the mouth, it passes through coarse baleen fibres. The small animals are trapped and swallowed.

3. In October as the days get shorter and ice begins to form. over the Arctic feeding grounds, the California grey whale begins its long journey south to the warm waters of Baja, California. During this three-month long trip the whales travelling in groups stay close to the shore of North America, swimming both day and night and averaging abut 100 miles per day.

4 During the trip south the grey whales that are sexually mature, at least three years old, and not pregnant already, form. mating groups. These groups are composed of three whales, two males and a female. The dominant male couples with the female while the second male is kept busy positioning the two whales on their sides facing each other and keeping them together during the sex act. This is no small job, since each whale can be fifty feet long and weigh forty tons.

5. During December and January the grey whales arrive at the warm lagoons along the coast of Baja, California. The whales swim miles inland along narrow shallow channels. These channels are the breeding grounds of the California grey whale. The calf has been gestating in the pregnant female for the last thirteen months, that is, since her last journey south. The expectant cow is aided in the birth of the calf by another female that acts as a midwife. At birth the calf sinks toward the sea floor. Being a mammal the whale must breathe at the surface. The midwife guides the baby whale to the surface for its first gulp of air. The calf then finds its mother&39;s nipples and rich whale milk is forced into its mouth. During the next two months the calf will grow twenty feet and double its weight.

6. In March the whales begin their long journey north to the Arctic. The newly-pregnant females leave first, following by the males and immature females. The last to leave the warm waters of Baja are the females and their calves. The whales arrive at their Arctic feeding ground in June. Many scientists believe that during this entire eight month long, 14,000 mile journey, the California grey whale does not feed at all!

Paragraph 3 ______

A. The Voyage Back B. An Arctic SummerC. Feeding Habits D. At the Breeding GroundsE. The Move SouthF. Mating

Paragraph 4 ______

A. The Voyage Back B. An Arctic SummerC. Feeding Habits D. At the Breeding GroundsE. The Move SouthF. Mating

Paragraph 5 ______

A. The Voyage Back B. An Arctic SummerC. Feeding Habits D. At the Breeding GroundsE. The Move SouthF. Mating

Paragraph 6 ______

A. The Voyage Back B. An Arctic SummerC. Feeding Habits D. At the Breeding GroundsE. The Move SouthF. Mating

A layer of blubber approximately six inches thick ______.

A. small shrimp-like animals called amphipods．B. protects the whale in Arctic waters.C. increase the circulation of its blood.D. two males and one female.E. leaves its Arctic feeding grounds,F. the surface of the water by a whale "midwife".

The whale feeds on______.

A. small shrimp-like animals called amphipods．B. protects the whale in Arctic waters.C. increase the circulation of its blood.D. two males and one female.E. leaves its Arctic feeding grounds,F. the surface of the water by a whale "midwife".

A mating group consists of ______.

A. small shrimp-like animals called amphipods．B. protects the whale in Arctic waters.C. increase the circulation of its blood.D. two males and one female.E. leaves its Arctic feeding grounds,F. the surface of the water by a whale "midwife".

The newly-born whale is assisted to _______.

A. small shrimp-like animals called amphipods．B. protects the whale in Arctic waters.C. increase the circulation of its blood.D. two males and one female.E. leaves its Arctic feeding grounds,F. the surface of the water by a whale "midwife".

请帮忙给出每个问题的正确答案和分析，谢谢！

Which is NOT true of sparklers？

A．They are harmless to very young children.

B．They are considered safe by many people.

C．They are a threat to the eyes.

D．They can burn at very high degrees Fahrenheit.

According to the passage, distance learning is basically characterized by ______.

A．a considerable flexibility in its academic requirements

B．the great diversity of students' academic backgrounds

C．a minimum or total absence of {ace-to-face instruction

D．the casual relationship between students and professors

What do peahens look for in peacocks？

A．Large wing feathers.

B．Loud mating calls.

C．Artistic tail displays.

D．Colorful breast plumag

Anthropology

Anthropology is the study of human beings as creatures of society. It fastens its attention upon those physical characteristics and industrial techniques, those conventions and values, which distinguish one community from all others that belong to a different tradition.

The distinguishing mark of anthropology among the social sciences is that it includes for serious study other societies than our own. For its purposes any social regulation of mating and reproduction is as significant as our own, though it may be that of the Sea Dyaks, and have no possible historical relation to that of our civilization. To the anthropologist, our customs and those of a New Guinea tribe are two possible social schemes for dealing with a common problem, and in so far as he remains an anthropologist he is bound to avoid any weighting of one in favor of the other. He is interested in human behavior, not as it is shaped by one tradition, our own, but as it has been shaped by any tradition whatsoever. He is interested in a wide range of custom that is found in various cultures, and his object is to understand the way in which these cultures change and differentiate, the different forms through which they express themselves and the manner in which the customs of any people function in the lives of the individuals.

Now customs has been commonly regarded as a subject of any great moment. The inner workings of our own brains we feel to be uniquely worthy of investigation, but custom, we have a way of thinking, is behavior. at its most commonplace. As a matter of fact, it is the other way round. Traditional custom is a mass of detailed behavior. more astonishing than what any one person can ever evolve in individual actions. Yet that is a rather trivial aspect of the matter. The fact of first-rate importance is the predominant role that custom plays inexperience and belief, and the very great varieties it may manifest.

According to the passage, we can say that anthropology______.

A．can reveal an enormous diversity of traditions

B．can deal with human beings as one group of the creatures in the living world

C．can provide insights into the relationship between human beings and nature

D．can distinguish the human race from other creatures

A．During mating season.

B．Except during the mating season.

C．All the year round.

D．Only in spring.

It is implied that the main difference between "S" and "R" rats is their ______.

A．need for Sodium 22

B．rate of mating

C．reaction to salt

D．type of blood

查看材料

A.quantities of salt consumed

B.choice of mating partner

C.blood pressure

D.reaction to salt

交配(mating)型的转变反应包括：

A．DNA盒(cassette)从沉默位点(HML或HMR)向MAT位点的移动。

B．通常导致交配型的转变。

C．在单倍体细胞中不发生。

It is implied in the second paragraph that ______.

A．a genetic factor is the main factor to develop high blood pressure

B．amount of salt eating is an important factor to develop high blood pressure

C．the rate to develop high blood pressure lies in the reaction to salt

D．high blood pressure can be affected by mating