DBS中单一逻辑工作单元的操作集合，称为（）。
参考答案：事务
With more forests being destroyed, huge quantities of good earth each year.
A．is washing away
B．is being washed away
C．are washing away
D．are being washed away
发动机增压方式有哪些？（）
A、机械增压
B、排气涡轮增压
C、气波增压
D、复合增压
