【单选题】以下描述属于滚子轴承工作特点的是()。
A.
球与滚道表面的接触为点接触,摩擦小,起动快,极限转速高,价格便宜,制造工艺简单,但承载能力差,耐冲击能力较低。
B.
滚子与滚道表面的接触为线接触,摩擦大,制造工艺复杂,价格较高,但承载能力、耐冲击能力较高。
【单选题】在OSPF同一区域(区域0)内,下列说法正确的是?( )
B.
每台路由器根据该最短路径树计算出的路由都是相同的
C.
每台路由器根据该LSDB计算出的最短路径树都是相同的
D.
每台路由器的区域A的LSDB(链路状态数据库)都是相同的
【单选题】What does 'temporary flooding of coastal areas' mean?
A.
The flooding caused by increased rainfall.
B.
The flooding caused by swamping of drainage system.
C.
The flooding caused by higher tides.
D.
The flooding caused by destruction of coastal structure.
【简答题】使用得最多的可编程序控制器编程语言是 (________), 它易被电气人员掌握。
【单选题】M.V. Blue Whale is flooding below water line
A.
The vessel is flooding in the engine room
B.
The vessel is flooding in holds
C.
The vessel is flooding below waterline
D.
The vessel is flooding in the fore peak tank
【简答题】滚动轴承的极限转速与 _____________ 和 ____________ 有关。
【简答题】The wall will act as a (defend)______ against flooding.