safe: implies the risk HAS been run WITHOUT incurring harm or damage: arrived home ~ and sound; or stresses freedom from risks: kept her ~ from harm;  or suggests a character that eliminates or mimimizes risks: ~ investment.


secure: usually stress freedom from anxiety and apprehension of danger or risk based on grounds that are sound and sufficient: ~ themselves from the harm.


safe: 三种可能 1) 经历了风险但未受损失，2) 免受风险， 3) 能消除或降低风险，secure: 不必焦虑担心<--完善充分的根据(grounds)。


记忆方法： 1）security是充分完善的safety。


                2）一般个人小范围用safety，团体大范围用security.

                   汉译英： 1. 人身安全       2. 国家安全
                   答案:  1. personal safety         2. national security
        
               3）安全的意思是免于危险风险mean free from danger or risk.