Development of the erv electricity feedback electro-hydraulic appropriate complex flux-control integrated blocks .

erv电反馈电液比例复合流量控制集成阀块的开发研究。

Most erv integrations will be negative or have no effect . The human genome is littered with the decayed remnants of such integrations , often reduced to fragments , or even solitary ltrs . This may explain the origin of retrotransposons .

大多数内源性逆转录病毒整合有负面影响或无作用效果，这种整合产生的无用基因充斥着人类基因组，使基因组沦为片段，甚至变成单个长末端重复序列，这种情况也许可以用来解释反转录转座子的起源。

H urry up , I hav e other people to s erv e.

快点，我还要招呼其他客人。

Once an erv is established in the genome , natural selection will act on it , weeding out viral genes or regulatory sequences that impair survival of the host , ignoring those that have no effect , and positively selecting the rare ones that enhance survival .

一旦内源性逆转录病毒在基因组中立足下来，自然选择就会对它施加作用，帮助除去妨碍宿主生存的有害病毒基因或者调控序列，同时忽视那些不起作用的基因，积极选择能增加生存几率的稀有基因。

Methods : vital capacity ( vc ) and its component expiratory capacity ( erv ) and inspiratory capacity ( ic ) were detected in non-smoking healthy volunteers before and after breathing helium-oxygen mixture and the changes were compared .

方法测定非吸烟健康志愿者呼吸氦氧混合气体前后肺活量及其组成补呼气容积和深吸气量并比较它们的变化。