The emperor penguin, an icon of Antarctica, has been declared an endangered species by the International Union for Conservation of Nature (IUCN). Its status was changed from “near threatened” to “endangered” as climate change pushes this bird closer to extinction. This decision highlights the serious threat that global warming presents to ice-dependent species.

Emperor penguins rely on sea ice to live, hunt and breed. The early break-up and loss of these frozen ocean platforms have caused their numbers to plummet. The IUCN predicts that climate-driven changes in sea ice could cut the population by half by the 2080s. Philip Trathan, part of the IUCN expert group, stated, “We concluded that human-induced climate change poses the most significant threat to emperor penguins.” On the IUCN Red List, which ranks species’ extinction risk, “endangered” is only two steps away from “extinction in the wild,” meaning a species survives only in captivity, living under human care in zoos and parks.

The largest of all penguins, emperor penguins have a brilliant golden-orange patch on their neck and chest. They breed on sea ice in the dead of winter; the males keep eggs warm beneath their feet. The sea ice also provides a habitat for chicks and is essential when they replace their feathers before becoming waterproof. But climate change is making the sea ice less stable, causing it to retreat or break up early in spring. Satellite images indicate around 20,000 adults — about 10% of the population — disappeared between 2009 and 2018. Christophe Barbraud, a scientist, said, “Since 2016-2017, there has been a significant decrease in the extent of sea ice around Antarctica, and therefore without sea ice, the species will struggle to survive.”

Trathan added that emperor penguins are a warning sign. The IUCN also listed the Antarctic fur seal as endangered; its numbers have plunged more than 50% since 1999. Rising ocean temperatures and shrinking sea ice push krill to deeper waters, reducing the seals’ food supply. In addition, the southern elephant seal was moved from “least concern” to “vulnerable” after its population declined due to a deadly contagious disease.

1.1. What does the underlined word “plummet” in Paragraph 2 probably mean?

A Fall rapidly.

B Expand gradually.

C Stay constant.

D Drop slightly.

解析：选A。A词义猜测题。由原文第二段的“The early break-up and loss of these frozen ocean platforms have caused their numbers to plummet.”可知，海冰提前消融消失，致使帝企鹅数量出现大幅变化。结合上下文气候变暖使其濒临灭绝的背景，可判断plummet意为快速骤降。B逐渐增长、C保持稳定和原文语境完全相悖，D小幅下降力度太弱，不符合物种生存危机的文意，因此选A。

2.2. According to Philip Trathan, what is mainly responsible for endangering emperor penguins?

A Natural climate cycles.

B Human-caused global warming.

C Shortage of breeding sites.

D Illegal hunting activities.

解析：选B。B细节理解题。原文第二段直接引用Philip Trathan的原话：“We concluded that human-induced climate change poses the most significant threat to emperor penguins.”，human-induced climate change即人类引发的全球变暖。A自然气候周期、C繁殖地不足、D非法捕猎在原文中均无任何文字依据，因此确定选B。

3.3. What can be inferred about emperor penguins from Paragraph 3?

A They can live without sea ice.

B Sea ice loss threatens their breeding.

C Males keep eggs warm on their feet.

D The decline had begun before 2009.

解析：选B。B推理判断题。根据原文第三段的“They breed on sea ice in the dead of winter; the males keep eggs warm beneath their feet. The sea ice also provides a habitat for chicks and is essential when they replace their feathers...”可知帝企鹅繁殖、孵蛋、幼崽成长全都依赖海冰，如今海冰变得不稳定、提前消融，由此能推断出海冰流失严重威胁其繁衍生育。A项和原文“without sea ice, it will struggle to survive”表意相反；C项为原文直接陈述的事实（第三段明确提到 the males keep eggs warm beneath their feet），并非“推断”得出；且原文用 beneath（在脚下方），选项用 on（在脚上方），表述亦不一致，故排除；D项原文仅提及2009至2018年数量减少，没有2009年之前数量下降的相关表述，均排除，故选B。

4.4. The two seal species in the last paragraph are mentioned to show ________.

A penguins are more endangered than seals

B only seals suffer from ice loss

C climate change threatens more than penguins

D diseases are destroying all ocean life

解析：选C。C推理判断题。前文全程围绕气候变化危害帝企鹅展开，最后一段提到“The IUCN also listed the Antarctic fur seal as endangered”以及南方象海豹生存状况变差，借助多种南极动物处境变差的事例，佐证气候变化的危害不止作用于帝企鹅，还威胁众多南极物种生存。A文中没有对比企鹅与海豹濒危程度；B“只有海豹受影响”违背全文主旨；D“疾病摧毁所有海洋生物”表述极端绝对，均不符合原文内容。故选C。