流程简单、能耗少、投资小、产品质量好是拜耳法生产氧化铝的优点
参考答案：对
I often see her _______ the piano. Listen, can you hear her _________ the piano now?
A．play, playing
B．plays, playing
C．playing, plays
D．play, plays
全塑电缆型号用G表示的特征是（）。
A.石油膏填充
B.自承式
C.高频隔离
