Question 3 is based on the news report you have just heard.

听力原文

        Summer doesn’t begin for two more days, (3) [but scientists are already sounding the alarm about dangerous ice melts going on right now in Greenland.] The vast island usually locks away enough fresh water in its ice sheet, which, if melted, can raise global sea levels by 6 meters. And research shows that in recent years, its ice has melted faster than ever before. This month, as temperatures in northwestern Greenland approach all-time highs, researchers are encountering unusual, surprising levels of melting ice in the region. The most significant concern here is how early this is all happening. Greenland experiences annual ice melt and growth cycles. (4) [But this year, the melting season began in early May. That’s a month earlier than normal] and something that’s happened only once before in the historical record, in 2016. That means that not only is the ice melting very fast, it has more time to melt this summer than it would in a normal climate system. Longer melt seasons like this one seem to lead to much greater contributions to sea-level rise than in previous decades.

3. What is scientists warning in the news report? （在这篇新闻报道中，科学家发出了何种警示？）

解析：B。录音开头提到，科学家们已经对格陵兰岛目前危险的融冰发出了警示。B项与此相符，全部为录音中的原词复现，故为正确答案。

错项排除：录音中提到了全球海平面的上升，但这并不是科学家警示的内容，故排除A项。C项的Changing weather patterns在录音中未提及，故排除。录音中说科学家警示的是冰盖的消融，而不是增长，D项与录音内容相悖，故排除。