【单选题】根据标准的适应领域和有效范围,安全技术防范标准分为四级,即国家标准、行业标准、地方标准、企业标准。那么,国家标准的代号是()
【单选题】企业标准由各企业自行编制、批准和在本企业范围内实施,其标准的代号为( )。
【简答题】已知字符串 s= '''Whether the weather be fine, or whether the weather be not. Whether the weather be cold, or whether the weather be hot. We will weather the weather whether we like it or not.''' 存放了一个英文绕口令...
【简答题】阅读理解。 TV news programs report the weather. Radio stations tell us the weather, too. Newspapers show us weather forecasts on maps. Why do people want to know about the weather? People want to make plan...