When burnt, plastic produces dangerous by-products.
塑料燃烧时产生出危险的副产品。
英语解释：a substance that is produced during the process of making or destroying sth else 副产品:
,
When burnt, plastic produces dangerous by-products.
塑料燃烧时产生出危险的副产品。
英语解释：a substance that is produced during the process of making or destroying sth else 副产品:
,
