When burnt, plastic produces dangerous by-products.

塑料燃烧时产生出危险的副产品。

One of the by-products of unemployment is an increase in crime.

失业带来的一大恶果是犯罪率上升。

He sold by-products of crude oil.

他卖原油的副产品。

One of these petroleum by-products is isoprene.

这些石油副产品之一便是异戊二烯。

It makes use of the numerous by-products from each process.

每一次反应后产生的为数众多的副产品同样能得到充分地利用。