静水中的球形颗粒，是在其本身重力的作用下而下沉的，同时又受到液体的浮力的抵抗，阻止颗粒下沉。
查看答案
升降舵感觉和定中组件的输入不包括（）。
A. 安定面配平马达
B. 马赫配平马达
C. 钢索
D. 自驾伺服作动器
列车检票次数原则上每：（）
A. 200公里一次
B. 300公里一次
C. 400公里一次
将N2通入起火的容器中，灭火的方法属于（）
A. 隔离法
B. 窒息法
C. 冷却法
What are three benefits of implementing vlans？（）
A more efficient use of bandwidth can be achieved allowing many physical groups to use the same network infrastructure
Broadcast storms can be mitigated by decreasing the number of broadcast domains，thus increasing their size
C. A higher level of network security can be reached by separating sensitive data traffic from other network traffic
D. Port-based vlans increase switch-port use efficient，thanks to 802.1Q trunks
E. A more efficient use of bandwidth can be achieved allowing many logical networks to use the same network infrastructure
F. Broadcast storms can be mitigated by increasing the number of broadcast domains，thus reducing theirsize
G. VLANs make it easier for IT staff to configure new logical groups，because the vlans all belong to thesame broadcast domai
微信支付 
支付宝支付