For an encore, he sang an unaccompanied folk song.应观众再唱一曲的要求, 他清唱了一首民歌.It is estimated that every year 50 unaccompanied children arrive in Britain.据估计，每年有50名儿童独自来到英国。Unaccompanied bags are either searched or removed.单独运送...
降低生活力或 “ 近亲繁殖的衰退 ” 并不是近亲繁殖必然的后果.Reduced vigor or " inbreeding depression " is not an invariable consequence of inbreeding.这些染色体畸变都是稳定的, 不影响细胞生活力的.These chromosome aberrations are all stable, compatible with cell viabilit...