His cheerful face brightens up the dullest of days.他的笑脸让最乏味的日子充满生气。The gel is guaranteed to add gloss even to the dullest hair.这种发胶能令即使是最没有光泽的头发也亮泽起来。He really is the dullest boy in the class.他确实是班上最笨的男生。This gel will add gloss to even the dullest hair.这种发胶即便最干枯的头发用了也会增添光泽。