双块式无砟轨道，排水通道应保持通畅，道床板表面不得（）。
参考答案：积水
The more ______ we take the safety standards, the further we can speed up the development
of the school bus industry. [ ]
A. constantly
B. generally
C. seriously
D. immediately
施工图就是在建筑工程中能十分准确地表达出建筑物的外形轮廓、大小尺寸、结构和材料做法的图样。( )
