排放超标的故障原因有喷油器喷油故障，燃油压力过高，点火高压弱，（）等。
A.油泵损坏
B.油管破裂
C.无高压火
D.传感器信号不准确
参考答案：D
The girl is often heard _______ in the next room.
A．sing
B．to sing
C．singing
D．sings
The CDs ____________ in the drawer(抽屉). [ ]
A. am
B. is
C. are
