简易铺装路面是指:()、()、()。
参考答案:沥青贯入式路面;沥青碎石路面;沥青表面处治路面
The situation put us at a serious ______, which made us very worried.
A.advantage
B.condition
C.disadvantage
D.situation
轨道电路分路状态的最不利条件是什么?