下列选项中，通常可采取( )方法处理电镀废水。
A．氧化还原法
B．混凝
C．活性污泥
D．离子交换
参考答案：A,B,D
At the beginning, he started his business with only a little money, but he built it up ______. [ ]
A. gradually
B. slowly
C. exactly
D. fluently
Access适合开发的数据库应用系统是______。
A．小型
B．中型
C．中小型
D．大型
