（1） Top dog：处支配地位者
　　In the present world, why should a country, often a super power, sometimes act as top dog over other countries?

　　（2） Go to the dogs：堕落；（经济）衰退
　　No matter a business or a country, if it is not properly managed, it is sure to go to the dogs one day.

　　（3） Do the donkey work：呆板的例常工作
　　Jack is not a person to work with. He will just sit back and let you do the donkey work.

　　（4） A sitting duck：容易被打击的对象
　　Out in the open, the hunter is a sitting duck for unseen wild animals.

　　（5） A cold fish：冷漠无情的人
　　Among the guests at the same table was Dr Wee's wife, who looked unfeeling and was a real cold fish to me .

　　（6） A fish out of water：如鱼离水；不适应
　　Qi never likes to go to a party, without friends, as he will feel like a fish out of water there.

　　（7） Have other fish to fry：另有更重要的事要干
　　As I had other fish to fry yesterday, I was forced to decline David's invitation to a dinner.

　　（8） There are plenty more fish in the sea：可供选择的人或事还很多
　　Since Andrew had gone off with another girl friend, Laura couldn't care less, knowing that there were plenty more fish in the sea.

　　（9） Cannot say boo to goose：羞怯
　　When foreign students first came here, they could not say boo to a goose, but there is now no shortage of eloquent speakers and outspoken thinkers.

　　（10） A wild-goose chase：徒劳的搜索
　　To look for a pin in the sea? Isn't it tantamount to a wild-goose chase?

　　（11） A guinea pig：被当实验的人或物
　　Whenever there is a research or something innovative, someone or something will be used as a guinea pig.

　　（12） Back the wrong horse：支持失败的一方
　　Many spectators backed the wrong horse by favouring the British team, which lost to the German team.

　　（13） A dark horse：实力难测的竞争者
　　No one expected Jimmy to win, but he did win. He was a dark horse.

　　（14） Change horses in mid-stream：半途改变主张，或支持另一方
　　If you support a person, do so from the beginning to the end; don't change horses in mid-stream.

　　（15） The lion's share of……：最大最好的部分
　　When the old man died, the eldest son took the lion's share of the inheritance.

　　（16） The rat race：激烈的竞争
　　In the rat race of today's world, only the fittest survives.

　　（17） A snake in the grass：潜伏的敌人
　　There has often been something suspicious about William's behaviour and he has really turned out to be a snake in the grass.