Question

 

Fishes are expected to be reduced in size by up to 24% because of global warming, say scientists.

Scientists believe that global warming has a greater effect on marine ecosystems (海洋生态系统) than previously thought. Previous researches have suggested that increasing ocean temperatures would affect both the distribution and the reproductive abilities of fishes. Now scientists believe that fish size would also be heavily affected.

Researchers built a model to see how fishes would react to the lower level of oxygen in water. Ocean temperatures increase and so do the body temperatures of fishes. But, according to the leading scientist Dr William Cheung, the lower level of oxygen in water is the key. Warmer waters could reduce the ocean oxygen level and greatly reduce fishes’ body weight. On the other hand, rising temperature directly increase the metabolic (新陈代谢的) rate of fishes’ body function. This leads to an increase in oxygen demand for normal body activities. So fishes will run out of oxygen for growth at a smaller body size.

The research group also used its model to predict fishes’ movements as a result of warming waters. The group believes that most fishes’ populations will move towards the Earth’s poles at a rate of up to 3.3 km per year.

Taking these factors into consideration, the research team concludes that fishes’ body size will be reduced by between 14% and 24%, with the largest reduction in the Indian and Atlantic Oceans.

When compared with the actual study of fish size, the model seems to make a lower judgment of what’s actually happening in the seas. The researchers made actual studies on some kinds of fishes living in the Atlantic Ocean. They found that the recorded data on these fishes showed greater reduction in body size than the models had predicted.

Scientists believe smaller-sized fishes could seriously affect the ability of fishes to reproduce (繁殖). Dr Alan Baudron, from the University of Aberdeen, the UK, thinks that smaller fishes produce fewer and smaller eggs and it could affect the reproductive potential of fishes.

68. From Paragraph 2 we can know that ________.

       A. scientists have made two researches on the influence of global warming by now.

       B. researchers suggest that the ocean temperature is increasing at a high rate.

       C. researches suggest that global warming would change fishes’ inner structure

       D. scientists have known three aspects of the influence that global warming has on fishes

69. Which is the most important factor that makes fishes smaller?

       A. Higher body temperatures of fishes.

       B. Lower oxygen level in water.

       C. Slower heart beats of fishes.

       D. Higher pressure in water.

70. According to the group, in 30 years, most fish populations will move about ________.

       A. 30 kilometers                                                    B. 60 kilometers         

C. 100 kilometers                                           D. 200 kilometers

71. Which of the following in the best title for the passage?

       A. Climate change may make fishes smaller.

       B. Global warming has a bad effect on fishes.

       C. Global warming affects the distribution of fishes.

       D. Climate change may affect the ability of fishes to reproduce.

 

Answer 1

DBCA