The drug is not harmful per se, but is dangerous when taken with alcohol.

　　這種藥本身無害，但與酒同服就危險了。

　　The drug is to be reclassified after trials showed it to be more harmful than previously thought.

　　試驗顯示這種藥比先前想象的危害更大，要重新歸類。

　　Such laws could protect the consumer from harmful or dangerous remedies

　　這樣的法規(guī)可以保護(hù)消費者免受有害或者危險藥品的威脅。

　　Mr Campbell said such programmes were by their very nature harmful

　　坎貝爾先生說此類節(jié)目本質(zhì)上就是有害的。

　　Radon is known to be harmful to humans in large quantities

　　眾所周知，大量的氡會對人體造成傷害。