The LAN-side of the Teleworker router is assigned private IP address space (RFC1918), and the VPN topology is IPSec-only (no GRE protocol). When is it required to configure NAT/pNAT on the Teleworker router?（） when all access to the Internet is through the IPSec tunnel。 when there is direct Internet access via split-tunneling。 when there is no Internet access configured through the Teleworker router。 whenever you have IOS-Firewall (CBAC) configured。
在困难情况下，地铁区间正线隧道平面曲线的最小半径应不小于（）m。 300。 250。 200。 150。
减压分馏
电子浓度
发动机正常工作时火花塞绝缘体裙部的温度应保持在（） 100~150℃。 250~350℃。 400~600℃。 500~700℃。
What is the phenomenon called where different wavelengths of light travel at different speeds？（）
