大同小异
much of muchness：The two articles are much of muchness ( be alike with minor difference ; There's not a pin to choose between the two ) in appearance and quality.

大言不惭
blow your own trumpet：You really blow your own trumpet. (talk big; overshoot oneself)

大快朵颐
They are so delicious that I ate my fill. (gorge oneself; tuck in at; have/take one's fill.) 

大功告成
The big project finally came off with honors (bring home the bacon; come through with flying colors).

大智若愚
He who cannot play the fool is not a wise man.

大器晚成
Rome was not built in a day.

大海捞针
needle in a haystack：Finding your lost contact lens is just like looking for a needle in a haystack.

山穷水尽
at the end of one's resources

山中无老虎，猴子称大王
Among the blind the one-eyed is king./When the cat's away, the mice will play.

小题大做
Make a mountain out of a molehill. ( fuss about trifles; a tempest in a teapot; a storm in a teacup; break a butterfly on a wheel )

小Car笔记：
much of a muchness：大同小异very much the same
tuck：<俚>大吃，通常后面接away/in
come off：实现，发生
bring home the bacon：成功，也有养家糊口，谋生的意思
play the fool：干蠢事，演滑稽角色 
contact lens：隐形眼镜

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