1．18．The phrase （短語） comes from anold interesting story．
19．Cats werecheaper than chickens，so many farmers would put cats into the cloth bag instead of chickens．
20..The woman wanted to see the chickenbefore paying the money．
21．The man's secret was out andeveryone\everybody knew it because the cat was out of the bag．
分析 略
解答 18．old interesting； 19．cheaper than； 20．before paying； 21．everyone\everybody knew
點評 略
