It filled the whole family with pride whenever the milkman exclaims on entering our gate, “What a sweet smell!” When the night-blooming cereuses are about to be in flower, we will invite some friends to visit us in the evening to feast their eyes on them—in an atmosphere smacking of nocturnal merry-making under candle lights. When the cereuses have branched out, we will pick some of the flowers and give them as a present to our friends. We are of course especially happy to see them take away our fruits of labour.译文：送牛奶的同志，进门就夸“好香”！这使我们全家都感到骄傲。赶到昙花开放的时候，约几位朋友来看看，更有秉烛夜游的神气——昙花总在夜里放蕊。花儿分根了，一棵分为数棵，就赠给朋友们一些；看着友人拿走自己的劳动果实，心里自然特别喜欢。） 有一段话我看不懂，in an atmosphere smacking of nocturnal merry-making under candle lights ，smack of是有点像的意思，为什么变成doing了，就是smack变成smacking了，我没理解，有大神指导吗？在下感激不尽