Question

    Sea turtles are one of several species that have temperature-dependent sex determination. The number of female babies increases when nests are made in warmer sands.

A recent study by the National Oceanic and Atmospheric Administration, California State University and Worldwide Fund for Nature Australia examined two genetically distinct populations of green sea turtles living in the Great Barrier Reef. The study found that a group of about 200,000 turtles living in the northern part of the reef was almost entirely female.

While the southern population was 65 to 69 percent female, females in the northern group accounted for 99.1 percent of young turtles and 86.8 percent of adults.

After combining their results with temperature data, the scientists in charge of the study found that the northern green turtles have been producing mainly females for more than two decades and that the complete feminization(雌性化) of this population is possible in the near future.

The temperature at which the turtles will produce male or female babies can be passed on to the turtles' children. Most sea turtle populations are now producing offspring above the most suitable temperature, making it clear that climate change causes a serious threat to the survival of these populations.

The chief executive Of World Wildlife Fund Australia, Dermot O'Gorman, said this is another sign of the impact of climate change, following recent research that shows that coral bleaching (珊瑚白化) events are occurring far more frequently than in the past.

“We've had two years where we've had mass bleaching events on the Great Barrier Reef,” he told Guardian Australia. “That's a very visible sign of the impact of climate change. But this is a quiet change. We can't see the impact it's having on a turtle population until a study like this shows some long-term trends.”

The lead author of the paper, Dr Michael Jensen, said the findings represent a major environmental conservation issue.

O'Gorman said more urgent action on climate change is clearly needed, adding that some conservationists have already taken practical measures, such as using shade cloth on turtle nesting beaches to lower the sand temperature, and reducing bycatch(误捕) in the fishing industry.

"Shade cloth can be used in certain places, but there's a limit to the scale you can do that, " he said. "Now every large male who can reproduce is going to be even more important.

1.According to the research on Great Barrier Reef's green sea turtles, __________.

A.about 65 to 69 percent of northern turtles are female

B.86.8 percent of southern turtles have grown up to adults

C.the feminization of green sea turtles could become worse

D.adult green Sea turtles can change their sex in warmer places

2.Why did O'Gorman mention coral bleaching?

A.To suggest that climate change poses more risks to coral than turtles.

B.To compare the living environments of turtles and coral.

C.To urge people to take practical measures to fight climate change.

D.To stress this discovery about green sea turtles is very valuable.

3.Conservationists are taking action to __________.

A.keep the sea turtles' nests cool

B.stop the illegal fishing of green sea turtles

C.expand the size of the green sea turtles' nesting places

D.build special nests for turtles to produce offspring

4.Which would be the best title for the article?

A.How climate change affects ocean creatures

B.Invisible change caused by global warming exposed

C.Necessity of protecting green sea turtles and their habitat

D.Global green sea turtle populations in greater danger

Answer

1.C

2.D

3.A

4.B

【解析】

这是一篇说明文。文章主要说明了全球气候变暖带来的问题，全球气候变暖使得绿海龟雌性化严重。环保人士正在采取行动，让海龟的巢穴保持凉爽。

1.细节理解题。根据第四段After combining their results with temperature data, the scientists in charge of the study found that the northern green turtles have been producing mainly females for more than two decades and that the complete feminization of this population is possible in the near future.可知负责这项研究的科学家们将研究结果与温度数据结合起来，发现北方绿海龟在20多年来一直以雌性为主，而且在不久的将来，这一种群完全雌性化是可能的。由此可知，根据对大堡礁绿海龟的研究，绿海龟的雌性化可能会变得更糟。故选C。

2.推理判断题。根据第七段中That's a very visible sign of the impact of climate change. But this is a quiet change. We can't see the impact it's having on a turtle population until a study like this shows some long-term trends.可知这是气候变化影响的一个非常明显的迹象。但这是一个悄无声息的变化。直到一项像这样的研究显示出一些长期趋势，我们才能看到它对海龟数量的影响。由此可推知，O'Gorman提到珊瑚白化是为了强调这一关于绿海龟的发现是非常有价值的。故选D。

3.细节理解题。根据倒数第二段O'Gorman said more urgent action on climate change is clearly needed, adding that some conservationists have already taken practical measures, such as using shade cloth on turtle nesting beaches to lower the sand temperature, and reducing bycatch in the fishing industry.可知O'Gorman说，显然需要采取更紧急的行动来应对气候变化。他补充说，一些环保人士已经采取了切实可行的措施，比如在海龟筑巢的海滩上使用遮荫布来降低沙子的温度，以及减少捕鱼业的副渔获物。由此可知，环保人士正在采取措施使海龟的巢穴保持凉爽。故选A。

4.主旨大意题。根据第二段中The study found that a group of about 200,000 turtles living in the northern part of the reef was almost entirely female.可知研究发现，生活在大堡礁北部的大约20万只海龟几乎全部是雌性。结合主要内容为说明气候变暖造成绿海龟的筑巢地温度升高，使其大面积雌性化，但是这一变化也是很难被观察到的，不过研究人员还是有了一些发现。故B选项“暴露全球变暖造成的无形变化”符合文章标题。故选B。