一般路基
参考答案：
指在良好的地质和水文等条件下，填方高度和挖方深度不大的路基。
《十九信条》
If you don't know how to spell a new word, you'd better ______. [ ]
A. look up a dictionary
B. look at a dictionary
C. look it up in a dictionary
D. look up it in a dictionary
