沥青的劲度模量主要取决于______。
A．沥青的化学成分
B．沥青的特性
C．荷载作用时间
D．路面工作温度
参考答案：A,B,C,D
We have finished the most of our work so far, and the rest _____ on time.
A．has been finished
B．has finished
C．will be finished
D．will finish
二阶系统的暂态分为( )种。
A．3
B．2
C．4
D．1
