单项选择题
A.双块式轨枕B.道床伤损C.底座板伤损D.支撑层伤损
A.CRTSⅠ型板式无砟道床B.CRTSⅡ型板式无砟道床C.道岔区轨枕埋入式无砟道床D.CRTSⅡ双块式无砟道床
A.低粘度树脂B.弹性聚氨酯C.水泥浆D.环氧树脂