When burnt, plastic produces dangerous by-products.
塑料燃烧时产生出危险的副产品。
《牛津词典》
2
Occurrences of food shortages and droughts are causing famine and distress in some areas, and industrial and agricultural by-products are polluting water supplies.
粮食短缺和干旱的出现导致了一些地区的饥荒和灾难，而且工业和农业的副产品也污染了水源。
3
Yet occurrences of food shortages and droughts are causing famine and distress in some areas, and industrial and agricultural by-products are polluting water supplies.