An icebreaker may use the code letter “K” to remind ships of their obligation to listen continuously on their radio. This signal may be made by any of the following EXCEPT（）. ["sound signal","light signal","visual signal","radiotelephone"]
三相电动机容量10千瓦，额定电流21安，起动时间6秒，起动电流是7倍额定电流值，应选择的熔体额定电流值（计算值）为（）安。 ["51.5","73.5","88.2","100"]
对于农信银系统银行汇票资金清算采取“（）”的清算方式。 ["签发时逐笔申请","逐笔圈存","解付时实时全额清算"]
以下是对标准的描述，正确的有（） ["标准只是一种文本","标准是一种特殊的文件","标准是一种规范性文件","标准是一种文件的汇集"]
以下配置中（）不是运行Windows 2000的最小要求。 ["486DX处理器或更新的处理器","128M的RAM","400～550MB的空闲硬盘空间","VGA卡"]
什么叫产业革命？世界上已发生了几次科技革命？它们对社会、生产的发展起到了什么作用？
