[填空题] 铅垂线是（）的基准线。

紊流粗糙区的沿程水头损失系数只与雷诺数有关。（） 在我国古代交友中，以下哪种称为是指情趣一致十分要好的朋友（）。 ["肺腑之交","莫逆之交","八拜之交"] 试述我国贷款风险分类的含义与主要内容，分析实行贷款风险分类法对贷款质量进行分类考虑的主要因素，并对商业银行实行贷款五级分类的主要意义进行阐述。 You are able to access a Web server from your computer by using the IP address of the Web server. You fail to access the Web server when you use its fully qualified domain name. Other users on your network can access the Web server by using both the IP address and the fully qualified domain name. You need to access the Web server by using the fully qualified domain name.  What should you do?（） ["A","B","C","D"] （）只接收数控系统发出的指令脉冲，执行情况系统无法控制。 ["半开环伺服系统","半闭环伺服系统","开环伺服系统","联动环伺服系统"] 铅垂线是（）的基准线。