Sent_en: 2zh Australia and the United States are the only developed nations to have refused to sign the Kyoto Protocol, which calls on countries to cut greenhouse emissions by 5.2 per cent below 1990 levels by 2012.
Sent_yy: 澳大利亚和美国是唯一拒绝签署京都议定书的两个发达国家。该议定书呼吁各国到2012年的时候，将温室排放减少到低于1990年水平的百分之5.2。