Limitations of this study include lack of data on prevalent influenza strains, insufficient power to assess the infrequent outcomes of influenza, and testing of only some of the infants for influenza.

这个研究的局限包括缺乏预防流感株的数据，评估罕见型流感的结果能力不足和仅仅对其中的一些患流感的患儿做检测。

youdao

Objective To study sequence variation of V3 loop of HIV-1 strains prevalent in China.

目的研究中国艾滋病病毒1型（HIV-1）毒株V3环序列的变异性。

youdao

Ransomware, which tries to make victims pay an on-the-spot fine, is becoming more prevalent but most strains simply accuse people of pirating movies or music.

BBC: Ransomware page