By 2020, China’s carbon dioxide emissions per unit of GDP will fall by 40-45 percent compared with those of 2005, the share of non-fossil fuels in primary energy consumption will rise to around 15 percent, the forest coverage will increase by 40 million hectares from 2005 level, and the forest stock volume will be 1.3 billion cubic meters more than that in 2005.
老师您好，我想问一下逗号不是不能连接完整的句子吗，可我上面这段话用了两个逗号连接的都是完整的句子，以上这段话来自17年下英语三笔汉译英的参考译文。
