11.The reverse is also true:反之亦然 12.Tie up with/busy with 13.Tired of/get bored of 14.Under the weather:身体不舒服 15.Well-off/rich people 16.White elephant:无价值的东西,废物 17.White lie:善意的谎言 18.You bet :当然 19.Take one’s time;从容不迫 20.Take one’s word:./believe in sb./trust sb.