Conclusion: the infection of human parvovirus B19 exists in the pregnant women in Zhengzhou, which may explain the unidentified reason abortion or stillborn foetus.

结论：郑州市孕妇中存在人微小病毒B19的感染，可能导致不明原因流产或死胎。

youdao

Through experiments the reason of unidentified flashover of composite insulators is seeked in this paper.

文章通过试验探索了合成绝缘子“不明原因”闪络的原因。

youdao

Unidentified Justice: The reason they don't believe you is because you're willing to take the money.

NPR: High Court Weighs On-Campus Military Recruitment