多媒体的关键特性有：（）
A.多样化
B.集成性
C.交互性
D.实时性
参考答案：A, B, C, D
粉尘爆炸
– The clothes here are not only of poor quality but also expensive.
– Peter _____ us a wrong place.
A．introduced
B．is introducing
C．had introduced
D．introduces
