气相色谱法测定环境空气和废气中挥发性卤代烃时,应定期测定吸附管前后活性炭的空白。
A. 正确
B. 错误
What three elements are included with Cisco Small Business Pro Service? ()
A. Software upgrades and updates
B. CiscoSMARTnet
C. next business day advanced hardware replacement
D. access to the Cisco Small Business Support Center
E. access to the Cisco Small Business University
F. five-year subscription term
软件、宾馆向顾客提供服务,按ISO9000精神均可称之为"产品"()
A. 正确
B. 错误
住宅作为物质实体,其结构寿命很长,而住宅的功能变化发展较快,基于两者的矛盾就要求()
A. 适当降低结构的生命周期
B. 住宅具有适应性及可变性
C. 加强住宅的工业化和产业化
D. 建造各种不同类型的住宅