Question

    A few weeks ago, scientists at Ukraine's Vernadsky Research Base in Antarctica found their usually white surrounds were covered in a shocking blood-red. For such a mess, the culprits behind this horrible scene are tiny.

“Our scientists have identified them under a microscope as Chlamydomonasnivalis(雪地衣藻),” said the National Antarctic Scientific Centre of Ukraine in a Facebook post.

These green algae, a type of seaweed, are common in all icy and snowy regions of Earth, from the Arctic to high mountain regions. They lie still during the freezing winter, but once the sunlight warms enough to soften their world, the algae awake, making use of the melt water and sunlight to rapidly bloom.

“The algae need liquid water in order to bloom,” University of Leeds microbiologist Steffi Lutz told Gizmodo in 2016. “The algal blooms contribute to climate change,” the center stated.

A study in 2016 showed that snow algal blooms can decrease the amount of light reflected from the snow by up to 13 percent across one melt season in the Arctic. “This will surely result in higher melt rates,” the researchers wrote.

In 2017 environmental scientists calculated that microbial communities contributed to over a sixth of the snowmelt where they were present in Alaskan ice fields. Their experiments showed that areas with more melt water led to the growth of 50 percent more algae and places with more algae melted further.

This Antarctic summer has certainly seen a lot more melt water than usual. Temperature records keep changing, leading to rapid melting previously only seen in the Northern Hemisphere.

1.What does the underlined word “culprits” in Paragraph 1 mean?

A.Risks. B.Chances.

C.Effects. D.Criminals.

2.What can we know about Chlamydomonasnivalis?

A.They can be found anywhere. B.They are sensitive to temperature.

C.They grow slower than before. D.They survive only one melt season.

3.What can be inferred from the last two paragraphs?

A.Ice and snow will soon disappear in the Antarctic.

B.Microbial communities bring about extreme weathers.

C.The Southern Hemisphere is warmer than the other parts.

D.Climate change and algae growth interact with each other.

4.Which can be a suitable title for the text?

A.Why Snow Turned Blood-red. B.How Algae Began in the Arctic.

C.Why Climate Changes Greatly. D.How the Snow Reflects Sunlight.

Answer

1.D

2.B

3.D

4.A

【解析】

这是一篇说明文。文章说明了几周前，乌克兰南极洲弗纳德斯基研究基地的科学家们发现，他们平时洁白的四周被一片触目惊心的血红色所覆盖，而造成这一现象的背后原因是雪地衣藻。文章介绍了雪地衣藻的习性，以及其与气候变化之间相互影响的关系。

1.

词义猜测题。结合后文behind this horrible scene are tiny可知此处指造成周围一片触目惊心的血红色这一恐怖场景背后的罪犯是小小的雪地衣藻。由此可知，划线单词“culprits”意思为“罪犯”。A. Risks.风险；B. Chances.机会；C. Effects.影响；D. Criminals.罪犯。故选D。

2.

细节理解题。根据第三段中They lie still during the freezing winter, but once the sunlight warms enough to soften their world, the algae awake, making use of the melt water and sunlight to rapidly bloom.可知它们在寒冷的冬天里静静地躺着，但一旦阳光温暖到足以软化它们的世界，藻类就会醒来，利用融化的水和阳光迅速开花。由此可知，雪地衣藻对温度很敏感。故选B。

3.

推理判断题。根据第四段“The algae need liquid water in order to bloom,” University of Leeds microbiologist Steffi Lutz told Gizmodo in 2016. “The algal blooms contribute to climate change,” the center stated.可知“藻类需要液态水才能开花，”利兹大学微生物学家Steffi Lutz在2016年告诉Gizmodo。该中心表示“藻类大量繁殖导致了气候变化”。由此可推知，气候变化与藻类生长相互作用。故选D。

4.

主旨大意题。根据第一段中A few weeks ago, scientists at Ukraine's Vernadsky Research Base in Antarctica found their usually white surrounds were covered in a shocking blood-red.可知几周前，乌克兰南极洲弗纳德斯基研究基地的科学家们发现，他们平时洁白的四周被一片触目惊心的血红色所覆盖。结合文章说明了造成这一现象的背后原因是雪地衣藻，介绍了雪地衣藻的习性，以及其与气候变化之间相互影响的关系。由此可知，A选项“雪为什么会变成血红色”最符合文章标题。故选A。