题目

They went(直接)home without stopping at the gas station, for it was too late. 答案：【1】straight如图，Rt△ABC中，∠ACB=90°，∠A=55°，将其折叠，使点A落在边CB上A′处，折痕为CD，则∠A′DB=（　　）A. 40° B. 30° C. 20° D. 10°