blue /blu:/ I. adj.1.蓝色的：The sky is deep blue. 天空蔚蓝。 His face was blue with cold. 他脸冻得发青。black and blue 青一块紫一块：He is black and blue all over. 他全身青一块紫一块。 2.悲观的：I’m feeling rather blue today. 我今天心情很差。‖II. n.［u］ & ［c］ 1.蓝色：A light blue would be a nice colour for the curtains. 浅蓝色是窗帘的适当颜色。2.忧郁：feel blue 没精打彩，灰溜溜的 3. 用于习语 out of the blue 突如其来：One day, out of the blue, she announced that she was leaving.一天她突然宣布要离开。