用几个短语造3个句子（前提：
问题描述：
用几个短语造3个句子（前提：
a white elephant 、a white night 、a white crow \the White House \a white lie \white flag\ black sheep\ black tea \black coffee \
black Dog \black gold\ green hand\ green tea \blue day \blue collar \blue fear
答
white elephant昂贵而无用之物The new office block has become an expensive white elephant.white flag白旗(承认失败,愿意停战)When the sky getting darker and darker,they finally waved the white flag.white ...