早期妊娠的确诊依据是（）
A.停经史
B.早孕反应
C.尿妊娠试验
D.黑加征
E.B型超声检查
参考答案：E
What made the whole nation sad was that more than 100 miners were buried in the underground coal mine.
A．live
B．living
C．alive
D．lively
下列哪个表示为国家强制性标准。（）.
A、“GB/T”
B、“GB”
C、“DA/T”
D、“DB”
