触类旁通comprehend by analogy

垂头丧气，无精打采 down in the mouth lose one’s spirits with the tail between the legs 

垂头丧气的blue about the gills crestfallen downhearted 来源：考试大

绰绰有余more than sufficient

此起彼伏as one falls,another rises

从容不迫go easy take one’s time 

从容不迫的leisured unhurried

从容不迫地by easy stages

粗枝大叶careless slapdash sloppy

粗枝大叶的broad-brush

措手不及unaware unprepared 来源：考试大

错综复杂、扑朔迷离 anfractuosity 

错综复杂的anfractuous daedal reticula sinuous

打草惊蛇act rashly and alert the enemy

大材小用waste one’s talent on a petty job

大公无私selfless

大海捞针look for a needle in a bottle of hay  来源：考试大

大惑不解be extremely puzzled

大惊小怪a storm in a teacup 、foofaraw 、fuss 、like a hen with one chicken 

大惊小怪的spoffish

大快人心affording general satisfaction

大名鼎鼎famous well known

大器晚成great minds mature slowly

大千世界the boundless universe

大失所望greatly disappointed

大同小异largely identical but with minor differences

大显身手、大显神通strut one’s stuff 

大言不惭、夸夸其谈fanfaronade rodomontade 

大义凛然inspiring awe by upholding justice

大义灭亲place righteousness above family loyalty