下列属于颈部关节活动的是:()、颈部绕环、颈部扭转、颈部拉伸。
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对于通信电源来说,负载均分是非常重要的,要求在小负荷情况下也必须均流。
A. 正确
B. 错误
()尾轴轴承虽然价格昂贵,但结构简单,具有抗腐蚀性,在水中的润滑性能好。
A. 白合金
B. 铁梨木
C. 桦木层压板
D. 橡胶
A preventer guy().
A. prevents anyone from working the cargo at unauthorized times
B. is a safety measure in case one of the outboard guys parts
C. is a longshoreman who watches for accidents
D. is the same as a blacksmith