There are a lot of puters in the lab,and they need professional to make sure they can be in a good state.
A. operation
B. maintenance
C. service
D. advice
网友回答
A. operation
(答案→)B. maintenance
C. service
D. advice
解析：operation操作；maintenance 维护,保持；service服务；advice建议。这里指计算机的专业维护。