《维规》规定,轨头下颏透锈长度超过()为重伤钢轨。
A. 20mm
B. 25mm
C. 28mm
D. 30mm
浮标运行历时≥100s,记至()s,运行历时≤100s,记至()s。
Which three of the following steps are mandatory when configuring MPLS on Cisco IOS? ()(Choose three.)
A. start LDP
B. enable CEF switching
C. configure the MPLS ID
D. disable IP TTL propagation
E. configure conditional label advertising
F. enable label switching on frame mode interface
催化重整生产芳烃的原料馏分范围应为()
A. 80-180℃
B. 60-145℃
C. 60-85℃
D. 85-110℃