(dated)merrymaking
(旧)寻欢作乐
(informal)something easily achieved
(非正式)容易的事
I never said that training him would be a piece of cake.
我从未说过对他进行训练会是小菜一碟。
(informal)be sold quickly and in large quantities
(非正式)销路很好;卖得快又多
(proverb)you can't enjoy both of two desirable but mutually exclusive alternatives
(谚)两者不可兼得