PLC中的内部器件有1和0两种状态,分别对应于继电器的接通“ON”、断开“OFF”两种状态。
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电压互感器以前简称为PT,文字符号为汉语拼音字头YH,现国家标准规定文字符号为()。
在没有外部供给能量的条件下,形核功依靠液体本身存在的()来供给。
实行单笔优惠汇率的业务,分支行在系统内手工输入汇率时要严格按照授权审批进行操作
A. 正确
B. 错误
In a married falls rig at the after end of a hatch,a boom is rigged in a fore and aft line through its heel.Stresses on the outboard guy will be LEAST if the guy is made fast at a point().
Abreast the heel
B. At right angles to the boom when viewed from above
C. Aft of the heel
D. Forward of the spiderband