对于钢结构的一级焊缝,可以采用的无损检测方法有()。
A. 超声波探伤
B. 射线探伤
C. 磁粉探伤
D. 渗透探伤
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Which three statements about end-to-end delay are true? ()
A. End-to-end delay is the sum of propagation delays, processing delays, serialization delays, and queuing delays.
B. Coast-to-coast end-to-end delay over an optical link is about 20 ms.
C. Processing delay depends on various factors, which include CPU speed, CPU utilization, IP switching mode, and router architecture.
D. Propagation and serialization delays are related to the media.
E. Propagation delay is the time it takes to transmit a packet and is measured in bits-per-second (bps).
F. Serialization delay is the time it takes for a router to take the packet from an input interface and put it into the output queue of the output interface.
墙体的保温分为外保温和内保温,外保温的保温性能远高于内保温。
A. 正确
B. 错误
作业人员应经相应的安全生产教育和岗位技能培训、考试合格,掌握本岗位所需的安全生产知识、安全作业技能和紧急救护法。
A. 正确
B. 错误
卷筒与其上所缠绕钢丝绳轮直径D与钢丝绳直径d之比D/d,对于一般起重机不小于(),对于()级工作类型的起重机则不小于()