【单选题】以下关于应力集中的说法中正确的是 ( )
B.
应力集中处易产生同号应力场,钢材的塑性变形受到限制 ,使钢材变脆
C.
应力集中处易产生异号应力场, 钢材塑性变形受到限制, 使钢材变脆
【单选题】I’m afraid I’m not _____to help with the talent show, for I am fully occupied with my own project.
【判断题】The poem you are listening to is "Ode to the Oaktree" by San mao.
【判断题】San Mao and Charlie Brown are both comic heroes of famous comic strips. (T/F)
【简答题】A.Both countries occupying San Juan Island. B.British ownership of the island. C.American ownership of the island. D.San Juan Island becoming independent.
【多选题】电子天平使用时应注意
A.
将天平置于稳定的工作台上避免振动、气流及阳光照射
D.
电子天平出现故障应及时检修,不可带“病”工作
【单选题】I’m fully occupied this week.
【多选题】电子天平使用时应注意
A.
将天平置于稳定的工作台上,避免震动,气流及阳光照射。
D.
电子天平出现故障时,应及时检修,不可带"病"工作。