印度尼西亚部分地区的森林大火已经持续燃烧了数周，烟雾不仅笼罩了该国，还蔓延至邻国马来西亚、新加坡和菲律宾。
Why is it so hard to put out Indonesian fires shrouding the region in toxic smog? Wildfires have been burning throughout parts of Indonesia for weeks, sending smoke across the country and into neighbouring Malaysia, Singapore and the Philippines.
英国广播公司（BBC）的加文·巴特勒（Gavin Butler）解释了为何这些火灾如此难以扑灭，以及为何会产生如此多有毒的烟霾。
The BBC’s Gavin Butler explains why the fires are so difficult to battle and produce so much toxic haze.