Question 11 is based on the passage you have just heard.

Passage One

听力原文

    During the Arctic winter from October to March, the average temperature in the frozen north typically hovers around minus 20 degrees Celsius. But this year, the Arctic is experiencing much higher temperatures.

    On February 20th, the temperature in Greenland climbed above freezing or zero degree Celsius and it stayed there for over 24 hours. (9) Then, on February 24th, the temperature on Greenland’s northern tip reached six degrees Celsius. Climate scientists described the phenomenon as stunning.

    (10) Weather conditions that drive this bizarre temperature surge have visited the Arctic before. They typically appear about once in a decade. However, the last such increasing temperature took place two years ago.

    This is troubling as climbing Arctic temperatures combined with rapid sea-ice loss are creating a new type of climate feedback loop which could accelerate Arctic warming. Indeed, sea-ice cover in the Arctic is melting faster than expected. Without those masses of cooling sea ice, warm air brought to the Arctic can penetrate further inland than it ever did before. The air can stay warmer, longer too. This drives additional melting.

    Overall, Earth is warming at a rapid pace—2014 through 2017 rank as the hottest years on record and the Arctic is warming twice as fast as any place else on Earth. This raises unique challenges for Arctic wildlife and indigenous people, who depend on Arctic ecosystems to survive.

    Previously, climate forecasts predicted that Arctic summer ice would disappear entirely by around 2060. (11) But based on what scientists are seeing now, the Arctic may be facing summers without ice within 20 years.

11. What may occur in 20 years according to scientists’ recent observations?

解析：B。原文中的but为重要提示词，科学家根据现在的景象推测，北极可能在20年内夏天就不会有海冰了，B选项中的Iceless对应原文中的without ice，因此本题选B。