The experts also noted that taking too much of some vitamins can be harmful.

VOA: special.2009.04.21

It's a common bacterium and most strains of E. Coli are not harmful to people, in fact, they provide us with some beneficial properties.

它是常见菌,且大多数种类的菌株对人类无害,实际上还给了我们颇多裨益

耶鲁公开课 - 生物医学工程探索课程节选

Some of the chemicals are harmful to both humans and animals.

VOA: special.2009.09.22