shelter: implies temporary protection of a screen or roof from something that would harm or annoy: seek ~ from the storm in a cave.   （screen遮挡屏蔽屏幕: 任何用来掩藏或遮挡的东西the shed is neatly screened by a hedge小屋被一道树篱巧妙地遮住）


cover: stresses concealment and often applies to a natural shelter or something similarly protective: advanced under ~ of darkness.


retreat: stresses usually voluntary retirement from danger or annoyance and escape to a safe, secure, or peaceful place: built themselves a country ~.


refuge: implies an attempt to flee from whatever threatens or harasses: sought ~ in the deserted house.  （词根FUG表示逃离to flee,escape，如fugitive逃犯，难以捕捉，centrifugal离心的，subterfuge骗人伎俩遁词,和本例）


asylum: adds to refuge the implication of the finding of safety and of exemption from seizure: asked for and was granted political ~.    (exempt免除责任或债务to free from a responsibility or liability，如his bad eyesight exempted him from military service他因视力不好免服兵役，they were exempted from paying the tax他们免于缴税）


sanctuary: stresses the claim of a refuge to reverence or inviolability: established a wildlife ~.    reverence崇敬=great respect


shelter遮蔽: 指暂时保护免于伤害或烦恼，如房顶或屏蔽物，cover掩盖: 强调有意遮蔽，常指自然的遮蔽物，retreat静居处: 强调自愿退避危险烦恼，到达安全宁静的地方，refuge避难: 表示逃离危险骚扰等，asylum庇护: 在refuge基础上增加了获得安全和免于抓捕的意思，sanctuary保护区: 表示保护地受崇敬不容侵犯


记忆方法： 1）首字母SCRRAS重组成SSCARR伤疤<==起保护作用

          2）保护的意思是安全的地方状态mean the state or a place where one is safe or secure from what threatens or disturbs.