辛凉解表药共有的功效是( )
A．清利咽喉B．清肺止咳C．透发麻疹D．发散风热E．清利头目
参考答案：D
What caused the accident and who was responsible for it ________ a mystery.[ ]
A. has remained
B. are remained
C. remains
D. remain
活塞杆填料函具有（）作用。
A．密封、刮油
B．刮油、分隔
C．密封、分隔
D．密封、刮油和分隔
