已知R、S是或非门构成的基本RS触发器的输入端，则约束条件为（）。
A. RS＝0
B. R＋S=I
C. RS＝l
D. R＋S=0
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粉喷桩施工应按设计要求进行重复搅拌，提升至接近地面时应采用（）。
A. 慢速
B. 中速
C. 快速
井下用机车运送爆炸材料时，炸药和电雷管不得在同一列车内运输。（）
A. 正确
B. 错误
Which of the following characteristics are true assuming you are troubleshooting a networkcurrently enabled for VRRP？（Choose all that apply.）（）
A. The network is load balancing among different members of the VRRP group
B. The default hello timers are 1 second
C. The interface IP address is being used as the virtual IP address
D. There are several routers in the group simultaneously forwarding traffic for the group
E. It is a Cisco Proprietary protocol
F. The default hello timers are 3 second
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