dangerous: applies to whatever may cause loss or harm unless dealt with carefully: soldiers on a ~ mission.


hazardous: implies great and continuous risk of harm or failure and small chance of successfully avoiding disaster: claims that smoking is ~ to your health.


precarious: suggests insecurity and uncertainty resulting from danger or hazard: has only a ~ hold on reality.


perilous: strongly implies the immediacy of danger: the situation at the foreign embassy has grown ~.   (immediate直接: 之间没有任何其他东西)


risky: often applies to a known and voluntarily accepted danger: shy away from ~ investments.   (shy away回避，避开:Alan doesn't shy away from controversy艾伦不回避争议 )


dangerous: 泛指任何可能造成损失或伤害，hazardous: 伤害严重持久，难免灾难，precarious: 由此导致的不安全不确定，perilous危急: 表示危险迫在眉睫，risky: 已知的，自愿接受的危险


记忆方法: 1) 首字母排序成PPDHR: 胖胖的好人，肥胖危害健康，善良容易被利用<==危险

                2) 危险的意思是可能导致损失或伤害mean bringing or involving the chance of loss or injury.