People diet to look more attractive. Fish diet to avoid being beaten up, thrown out of their social group, and getting eaten as a result. That is the fascinating conclusion of the latest research into fish behavior by a team of Australian scientists.

The research team have discovered that subordinate fish voluntarily diet to avoid challenging their larger competitors. “In studying gobies we noticed that only the largest two individuals, a male and female, had breeding （繁殖） rights within the group,” explains Marian Wong. “All other group members are nonbreeding females, each being 5-10% smaller than its next largest competitor. We wanted to find out how they maintain this precise size separation.”

The reason for the size difference was easy to see. Once a subordinate fish grows to within 5-10% of the size of its larger competitor, it causes a fight which usually ends in the smaller goby being driven away from the group. More often than not, the evicted fish is then eaten up.

It appeared that the smaller fish were keeping themselves small in order to avoid challenging the boss fish. Whether they did so voluntarily, by restraining how much they ate, was not clear. The research team decided to do an experiment. They tried to fatten up some of the subordinate gobies to see what happened. To their surprise, the gobies simply refused the extra food they were offered, clearly preferring to remain small and avoid fights, over having a feast.

The discovery challenges the traditional scientific view of how boss individuals keep their position in a group. Previously it was thought that large individuals simply used their weight and size to threaten their subordinates and take more of the food for themselves, so keeping their competitors small.

While the habits of gobies may seem a little mysterious, Dr. Wong explains that understanding the relationships between boss and subordinate animals is important to understanding how hierarchical （等级的） societies remain stable.

The research has proved the fact that voluntary dieting is a habit far from exclusive to humans. “As yet, we lack a complete understanding of how widespread the voluntary reduction of food intake is in nature,” the researchers comment. “Data on human dieting suggests that, while humans generally diet to improve health or increase attractiveness, rarely does it improve long-term health and males regularly prefer females that are fatter than the females’ own ideal.”

1.When a goby grows to within 5-10% of the size of its larger competitor, it        .

2.The underlined words “the evicted fish” in Paragraph 3 refer to        .

3.The experiment showed that the smaller fish        .

4.What is the text mainly about?

Of all living creatures on earth, insects are the most plentiful. Some 1 are very useful to man, for example, bees, 2 we get honey and wax, and silkworms, which 3 us with silk. Other varieties, 4 , are extremely harmful, and do a great 5 of damage, especially to crops. Locusts are perhaps the most dangerous of all, 6 they will eat almost any green 7 , and when millions of them 8 on cultivated land they soon leave it 9 . In some countries they are the farmers’ 10 enemy. Another nuisance is the common 11 , not only because it 12 us indoors and out-of-doors, but because it spreads diseases.

　　Scientists have given much time and 13 to the study of insects. It needs the most careful and 14 observation. Thanks 15 their discoveries we now know almost all 16 is to be known about the habits of these hardworking insects, bees and ants, which live in 17 better planned in some ways than our 18 . But the most valuable work has been done in trying to give 19 to men, animals and crops from the 20 which insects cause.

1．A．members             B．forms         C．qualities            D．varieties

2．A．by which             B．from which     C．of which            D．in which

3．A．give                 B．produce         C．offer               D．supply

4．A．however              B．meanwhile      C．offer              D．supply

5．A．majority              B．number         C．amount            D．what’s more

6．A．and                  B．for             C．if                 D．when

7．A．grass                B．field           C．fruit               D．plant

8．A．settle                B．attack          C．pass               D．cross

9．A．bare                B．nothing         C．empty              D．untouched

10．A．hardest             B．greatest         C．serious             D．wildest

11．A．insect               B．creature        C．fly                D．enemy

12．A．dislikes             B．bites           C．worries            D．hates

13．A．understanding        B．ideas            C．comprehension       D．thought

14．A．serious             B．patient         C．curious            D．long

15．A．for                 B．of             C．to                 D．with

16．A．that                B．which         C．there              D．what

17．A．societies             B．crowds         C．teams              D．organizations

18．A．world               B．nation       C．selves              D．own

19．A．help               B．protection    C．living              D．defense

20．A．injury               B．wound        C．sickness             D．ruin

People diet to look more attractive. Fish diet to avoid being beaten up, thrown out of their social group, and getting eaten as a result. That is the fascinating conclusion of the latest research into fish behavior by a team of Australian scientists.

The research team have discovered that subordinate fish voluntarily diet to avoid challenging their larger competitors. “In studying gobies we noticed that only the largest two individuals, a male and female, had breeding （繁殖） rights within the group,” explains Marian Wong. “All other group members are nonbreeding females, each being 5-10% smaller than its next largest competitor. We wanted to find out how they maintain this precise size separation.”

The reason for the size difference was easy to see. Once a subordinate fish grows to within 5-10% of the size of its larger competitor, it causes a fight which usually ends in the smaller goby being driven away from the group. More often than not, the evicted fish is then eaten up.

It appeared that the smaller fish were keeping themselves small in order to avoid challenging the boss fish. Whether they did so voluntarily, by restraining how much they ate, was not clear. The research team decided to do an experiment. They tried to fatten up some of the subordinate gobies to see what happened. To their surprise, the gobies simply refused the extra food they were offered, clearly preferring to remain small and avoid fights, over having a feast.

The discovery challenges the traditional scientific view of how boss individuals keep their position in a group. Previously it was thought that large individuals simply used their weight and size to threaten their subordinates and take more of the food for themselves, so keeping their competitors small.

While the habits of gobies may seem a little mysterious, Dr. Wong explains that understanding the relationships between boss and subordinate animals is important to understanding how hierarchical （等级的） societies remain stable.

The research has proved the fact that voluntary dieting is a habit far from exclusive to humans. “As yet, we lack a complete understanding of how widespread the voluntary reduction of food intake is in nature,” the researchers comment. “Data on human dieting suggests that, while humans generally diet to improve health or increase attractiveness, rarely does it improve long-term health and males regularly prefer females that are fatter than the females’ own ideal.”

1.When a goby grows to within 5-10% of the size of its larger competitor, it        .

A. faces danger                      B. has breeding rights

C. eats its competitor                                 D. leaves the group itself

2.The underlined words “the evicted fish” in Paragraph 3 refer to        .

A. the fish beaten up                B. the fish found out

C. the fish fattened up              D. the fish driven away

3.The experiment showed that the smaller fish        .

A. fought over a feast                                 B. went on diet willingly

C. preferred some extra food         D. challenged the boss fish

4.What is the text mainly about?

A. Fish dieting and human dieting.

B. Dieting and health.

C. Human dieting.

D. Fish dieting.

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

(71 )    When a person does a certain thing again, he is impelled(迫使) by some unseen force to do the same thing repeatedly; thus a habit is formed. Once a habit is formed, it is difficult, and sometimes impossible, to get rid of.   (72)     Children often form bad habits, some of which remain with them as long as they live. Older persons also form bad habits as long as they live, and sometimes become ruined by them.

(73)    Many successful men say that much of their success has something to do with certain habits in early life, such as early rising, honesty and thoroughness.

Among the habits which children should not form are laziness, lying, stealing and so on. (74)    Unfortunately older persons often form habits which ought to have been avoided.

(75)      

A. There are other habits which, when formed in early life, are of great help.

B. Whether good or not habits are, they are easy to get rid of.

C. We ought to keep from all these bad habits, and try to form such habits as will prove good for ourselves and others.

D. Habits, whether good or bad, are gradually formed.

E. It is very important for us to know why we should get used to good habits.

F. These are all easily formed habits.

G. It is therefore very important that we should pay great attention to the formation of habits.

Why don’t birds get lost on their long migratory (迁居的) flights? Scientists have puzzled over this question for many years. Now they’re beginning to fill in the blanks.

Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly mainly by night? Tests with artificial stars have proved conclusively that certain night-flying birds are able to follow the stars in their long-distance flights.

One such bird, a warbler(鸣禽) , had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The bird’s cage was placed under an artificial star-filled sky at migration time. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the direction of the make-be-live stars caused a change in the direction of his flight. Scientists think that warblers, when flying in daylight, use the sun for guidance. But the stars are apparently their main means of navigation (导航). What do they do when the stars are hidden by clouds? Apparently, they find their way by such landmarks as mountain ranges, coast lines, and river courses. But when it’s too dark to see these, the warblers circle helplessly, unable to get their direction.

1.The reasons why birds don’t get lost on migratory flights__________.

2.Warblers migrate__________.

3.When the stars are hidden by clouds, warblers find their way by__________ .

4.This article is a good example of the way scientists__________ .