Question 4 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.

4. What do we learn about this year’s ice melting season in Greenland?（关于格陵兰岛的融冰季，我们能了解到什么？）

解析：C。录音后半部分提到，今年，融化季从5月初就开始了（began），比正常情况早了一个月（a month earlier than normal）。C项与此相符，其中的started是对录音中began的同义替换，a month earlier than usual是对录音中a month earlier than normal的同义替换，故为正确答案。

错项排除：录音中说融冰季开始于5月初，故A项错误。B项内容在录音中未提及，故排除。录音中说融冰季比以往早一个月开始，而不是比之前提前一个月结束，故D项错误。