使用过程中的维护、维修、更新改造文件材料，按（）文件材料整理归档。
A、设备仪器
B、电气工程
C、通信工程
D、消防工程
参考答案：A
My aunt is good at bargaining and she always buys things at a ________. [ ]
A. discount
B. cost
C. price
D. benefit
--- Which is the smallest number of the four?
--- _________.
A．Two- thirds
B．A half
C．A quarter
D．Three-fourths
