put sb. on (或upon) the spot使某人处于难堪地位;为难某人

　　between a rock and a hard place左右为难,进退两难

　　the horns of a dilemma左右为难的处境

　　in a pickle在困境中

　　in a tight spot在困境中,在窘境中

　　in the middle夹在中间,左右为难

　　between two fires遭两面夹攻

　　between the devil and the deep blue sea进退两难

　　between Scylla and Charybdis腹背受敌,进退两难

　　between the hammer and the anvil腹背受敌,被两面夹攻

　　Hobson’s choice无选择余地的选择

　　catch-22叫人左右为难的规定