比较级more harmful，最高级是mostharmful，中文意思是adj. 有害的，造成伤害的
Effluent from the sedimentation tank is dosed with disinfectant to kill any harmful organisms.从沉降池流出的废水被加入消毒剂以***死一切有害生物。
Womens' magazines just don't publish articles on the harmful effects of smoking.
