sea ice ,air pollution两个词为什么不能看做普通名词构成的专有名词?

sea ice ,air pollution两个词为什么不能看做普通名词构成的专有名词? Air there ice creams in the shop?(否定回答) will you travel by sea or by air的意思! Sea-to-Air Defense怎么翻译比较好? will you travel by sea or air?和will do travel by sea or air?哪一句是对的 ICE ice ice Ice Ice ea字母组合发[ i：],至少5个（除eat,ice cream,read,sea） 什么是物质名词物质名词都是不可数吗?比如sea ice what do they eat for dinner,ice-cream or sea food? （ ）Polar bears live mostly on _____ sea ice.A.a B.an C./ D.the 关于by sea的问题.比如说：by sea/by air /by land等,by前面要加定冠词吗? will you travel by sea or air?和will you do travel by sea or air?哪一句是对的 sea Sea