根据短文内容,从下边的A—F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余选项。 A.Thedi...
问题详情:
根据短文内容,从下边的A—F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余选项。
A . The different structure of blue holes.
B. Why scientists are interested in blue holes.
C. How a blue hole comes into being.
D. Blue holes exploring is becoming popular.
E. Rules to obey when diving into blue holes.
F. The general definition of a blue hole.
61. ______________
A blue hole is a flooded sea cave with a hole that opens up at the land's surface. These cave systems form in carbonate rock, often on islands. Some blue holes have very special rock formations and water chemistry. Far below sea level, they contain some of the harshest environments on Earth, with no oxygen and no light. Yet these areas are filled with life forms that have adapted to the extreme conditions.
62. ____________
Blue holes get their name from the color some have when seen from the air. The color is usually a reflection of the sky on the water. Blue holes are the result of erosion in which water breaks down rock. Rain falling thousands of years ago contained chemicals which slowly wore away at the limestone landmass. These holes later filled with sea water as the sea level changed. The rising and falling of sea levels and the mixture of salt and fresh water further wore away at these cave formations.
63. ____________
These flooded cave systems can be found in the ocean, or they can be found inland. Ocean caves are affected by tides, so they always have water movement. But blue holes on land are very still. They have several layers of water, chemicals, and bacteria. The top layer of fresh water comes from rainfall. This layer acts like a cap on top of the layered mixture, and keeps out oxygen from the atmosphere. The fresh water floats on a denser layer of saltwater. Underneath this is a layer of poisonous hydrogen sulfide, produced by bacteria living in the water. Underneath this layer is anoxic seawater -- water that does not contain any oxygen.
64. ___________
Information gathered from these blue holes is helping scientists to increase their understanding of biology, archaeology and geology. But exploring these blue hole environments brings danger as well as discovery. Scientists are interested in these caves because oxygen-free conditions there are similar to those on Earth long ago, before oxygen existed on our planet. But there are many difficulties involved in diving into blue holes.
65. ___________
One reason blue holes have not been fully explored is that they can be extremely dangerous. There are many safety rules that divers must follow to help ensure their survival. First, divers must have training and experience to swim in these caves. Divers who explore a cave for the first time must establish a thin rope called a guideline. This line helps them to safely enter and exit the cave without getting lost.
【回答】
FCABE
知识点:其他
题型:信息匹配
-
右图是*、乙的溶解度曲线,下列说法不正确的是 A.t1℃时,乙的溶解度大于*的溶解度B.t2℃时,*、乙的饱和...
问题详情:右图是*、乙的溶解度曲线,下列说法不正确的是 A.t1℃时,乙的溶解度大于*的溶解度B.t2℃时,*、乙的饱和溶液中溶质的质量分数相等C.降低温度能使接近饱和的*溶液变为饱和溶液D.t3℃时,75g*的饱和溶液中加入50g水,可以得到质量分数为25%的溶液【回答】D知识点:溶...
-
在下列向量组中,可以把向量表示出来的是( )A B. C. D.
问题详情:在下列向量组中,可以把向量表示出来的是( )A B. C. D. 【回答】知识点:高考试题题型:选择题...
-
2003年楚人学舟楚①人有习*舟者,其始折旋②疾徐,惟舟师之是听。于是小试洲渚之间,所向莫不如意,遂以为尽*舟...
问题详情:2003年楚人学舟楚①人有习*舟者,其始折旋②疾徐,惟舟师之是听。于是小试洲渚之间,所向莫不如意,遂以为尽*舟之术。遽谢舟师,椎③鼓径进,亟犯④大险,乃四顾胆落,坠桨失柁⑤。【注释】①楚:古国名。②折:调头。旋:转弯。③椎:用椎敲。古代作战,前进时以击鼓为号。④亟...
-
下列对诗句分析不正确的一项是( )A.“关关雎鸠,在河之洲”两句运用比喻手法,说明淑女、君子在河滩幽会,营造...
问题详情:下列对诗句分析不正确的一项是()A.“关关雎鸠,在河之洲”两句运用比喻手法,说明淑女、君子在河滩幽会,营造出一种幽静的氛围。B.“参差荇菜”一句反复使用,增强了诗歌的节奏感,也展现了《诗经》回环往复、一唱三叹的特*。C.“悠哉悠哉,辗转反侧”以行动来反映君...
相关文章
- 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。FiveThingsAmbi...
- 阅读理解七选五根据短文内容,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。 Tear...
- 任务型阅读 根据短文内容,从短文后的七个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。Inthec...
- 根据短文内容,从下框的A~F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余项。A.Giftgivin...
- 根据短文内容,从下框的A~F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余项。 A.Whydope...
- 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。Thewordaddicti...
- 阅读短文,根据短文内容,从短文后的五个选项中选出能填入空白处的最佳选项。选项中有一项为多余选项。 Thetwe...
- 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。Ifanyonehadtol...
- 阅读短文,根据短文内容,从短文后的五个选项中选出能填入空白处的最佳选项。选项中有一项为多余选项。Reading...
- 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。Itmaybedifficu...