单选题In fisheries in general, when a large harvest is taken one year, there will be fewer fish available to be harvested in the following year, leading to decreasing yields of most fish species over time. The Maine lobster is an anomaly, however. Even thoug

_________the new pop singer built her first album piece by piece.

A． Over a year and a half

B． Over half and a year

C． Over one and a half year

D． Over year and half

C

GUATEMALA CITY （Reuters） – A fish that lives in mangrove swamps（红树沼泽）across the Americas can live out of water for months at a time, similar to how animals adapted（适应）to land millions of years ago, a new study shows.

The Magrove Rivulus, a type of small killifish, lives in small pools of water in a certain type of empty nut or even old beer cans in the mangrove swamps of Belize, the United States and Brazil. When their living place dries up, they live on the land in logs（圆木），said Scott Taylor, a researcher at the Brevard Endangered Lands Program in Florida.

The fish, whose scientific name is Rivulus marmoratus, can grow as large as three inches. They group together in logs and breathe air through their skin until they can find water again.

The new scientific discovery came after a trip to Belize.

“We kicked over a log and the fish just came crowding out,” Taylor told Reuters in neighboring Guatgemala by telephone. He said he will make his study on the fish known to the public in an American magazine early next year.

In lab tests, Taylor said he found the fish can live up to 66 days out of water without eating.

Some other fish can live out of water for a short period of time. The walking catfish found in Southeast Asia can stay on land for hours at time, while lungfish found in Australia, Africa and South America can live out of water, but only in an inactive state. But no other known fish can be out of water as long as the Mangrove Rivulus and remain active, according to Patricia Wright, a biologist at Canada’s University of Guelph.

Further studies of the fish may tell how animals changed over time.

“These animals live in conditions similar to those that existed millions of years ago, when animals began making the transition（过渡）from water onto land,” Wright said.

49. The Mangrove Rivulus is a type of fish that _______.

A. likes eating nuts

B. prefers living in dry places

C. is the longest living fish on earth

D. can stay alive for two months out of water

阅读下面短文，根据短文内容，在短文后８１－８５小题中句子空白处填入适当的词语或句子。

We know that many animals do not stay in one place. Birds, fish and other animals move from one place to another place at a certain time. They move for different reasons: most of them move to find food more easily, but others move to get away from places that are too crowded.

When cold weather comes, many birds move to warmer places to find food. Some fishes give birth in warm water and move to cold water to feed. The most famous migration is probably the migration of fish, which is called “salmon”（鲑鱼）. This fish is born in fresh water but it travels many miles to salt water. There it spends its life. When it is old, it returns to its birthplace in fresh water. Then it gives birth and dies. In northern Europe, there is a kind of mouse. They leave their mountain homes when they become too crowded. They move down to the low land. Sometimes they move all the way to the seaside, and many of them are killed when they fall into the sea.

Recently, scientists have studied the migration of a kind of lobster(龙虾). Every year, when the season of the bad weather arrives, the lobsters get into a long line and start to walk across the floor of the ocean. Nobody knows why they do this, and nobody knows where the go. So, sometimes we know why humans and animals move from one place to another place, but at other times we don’t. Maybe living things just like to travel.

81. The reason for most of the animals to move is _____________________.

Millions of pounds’ ____ of fish is caught every year around the coasts of Britain.

A: worth

B: worthy

C: worthwhile

D: worthless

Large fish usually ____ small fish.

A：gather

B：take on

C：feed on

D：organize

Text 3

When prehistoric man arrived in new parts of the world, something strange happened to the large animals. They suddenly became extinct. Smaller species survived. The large, slow-growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.

That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.

Dr. Worm acknowledges that the figures are conservative. One reason for this is that fishing technology has improved. Today’s vessels can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines would have been more saturated with fish. Some individuals would therefore not have been caught, since no baited hooks would have been available to trap them, leading to an underestimate of fish stocks in the past. Furthermore, in the early days of longline fishing, a lot of fish were lost to sharks after they had been hooked. That is no longer a problem, because there are fewer sharks around now.

Dr. Myers and Dr. Worm argue that their work gives a correct baseline, which future management efforts must take into account. They believe the data support an idea current among marine biologists, that of the “shifting baseline.” The notion is that people have failed to detect the massive changes which have happened in the ocean because they have been looking back only a relatively short time into the past. That matters because theory suggests that the maximum sustainable yield that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels. Most fisheries are well below that, which is a bad way to do business.

31. The extinction of large prehistoric animals is noted to suggest that ________.

[A] large animal were vulnerable to the changing environment

[B] small species survived as large animals disappeared

[C] large sea animals may face the same threat today

[D] slow-growing fish outlive fast-growing ones

Why is it a problem if all the smaller fish species die?

A. It's not healthy for the environment.

B. People only like to catch big fish.

C. There are too many small fish.

D. The smaller fish can get lost in the lake.

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

which of the following is not one of the major exports of new zealand?

A. Wool.

B. Oil.

C. Dairy products. .

D. Fish.

Fish is______and expensive at this time of the year in this area.

A．in large measure

B．to the minimum

C．in short supply

D．to the maximum