Fact Check: Study did not say 1.7 million children had heart defects after COVID vaccine
A COVID-19 study in Britain looked at the medical records of 1.7 million children but did not conclude the same number of ...
GB/T 7251.1-20232013 差异点解读分析1.7 “使用条件” 的差异12
GB/T 7251.1-2023 与 GB/T 7251.1-2013 差异点解读分析 1.7 “使用条件” 的差异 污染等级(见3.6.9 )是指成套设备所处 的环境条件。 对于外壳内的开关器件和元件，可使 用外壳内环境条件的污染等级。