高速公路、一级公路沥青路面应采用( )。
A．沥青混凝土混合料面层
B．沥青贯人式面层
C．乳化沥青碎石面层
D．沥青表面处治面层
参考答案：A
Both the police and the workmen were grateful to the student for _______ in advance. [ ]
A. they had been informed this
B. their informing of this
C. informing them of this
D. having informed them this
实验室收集二氧化硫气体，应选用的装置是[ ]
A.
B.
C.
D.
