let alone Not to mention; much less: 更不用提;更别说: “Their ancestors had been dirt poor and never saw royalty,let alone hung around with them”(Garrison Keillor) “他们的祖先穷得要命,从来没有见过王族成员,更不用说和他们在一起了”(加里森·谢勒) There isn't enought room for us,let alone six dogs and a cat I haven't decided on the menu yet,let alone bought the food. I haven't decided where to go,let alone when to leave. 没有见过to do的用法