知识扩展
 
English has many "compound" words, that is, words that are made up of two complete words. Take a look at the following:
 
英语中有大量的复合词，其由两个单词结合在一起组成。例如：
 armchair n.扶手椅子 arm chair
 baseball n.棒球 base ball
 classmate n.同班同学 class mate
 evergreen n.常绿植物 ever green
 breakfast n.早餐 break fast
 grasshopper n.蝗虫 grass hopper
 tiptoe n.脚尖，趾尖 tip toe
 weekend n.周末 week end
 trademark n.商标 trade mark
 popcorn  n.爆米花 pop com