_________________________This is the first time it's made its commitments to the United Nations. It's part of the great endeavor to tackle climate change at the UN climate summit later this year." World news from the BBC. ____________________这是中国首次就污染问题向联合国做出承诺.这也是中国为今年下半年举行的联合国气候峰会上解决气候变化问题所做的部分努力.以上是BBC 全球新闻.