Myparentsliveinasmal的精选

问题详情： Myparentsliveinasmallvillage.Theyalwayskeepcandlesinthehouse________thereisapowercut.A.ifB.unlessC.incaseD.sothat【回答】【解析】选C。考查动词时态。句意为：——使用手机对人们的健康有害吗？——科...