多项选择题反光膜抗冲击性能试验后,在受到冲击的表面以外,不应出现( )。A. 裂缝B. 层间脱离C. 老化D. 破碎
单项选择题How many periods of time can the development of the three major parties in UK be divided into?A.twoB.threeC.fourD.five