_____ the help of my teacher, I've improved my English.[ ]
A. By
B. With
C. Under
D. For
答案:B
CRTSⅡ型板式无砟道床路基地段道床结构由()等部分组成。
A.轨道板
B.水泥乳化沥青砂浆充填层
C.混凝土底座
D.支撑层