当前民航使用频率间隔是25kHz，当R/SXU250A出现以下哪个告警不影响工作（）
A. “Warning 01 ” NO Remote
B. “Warning 08” Frequ Range
C. “Warning 18” Frequ Spacing
D. “Warning 16” Tx Filt. Absent
企业的厂房、设施、设备和检验仪器应当经过验证。
A. 正确
B. 错误
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
微信支付 
支付宝支付