True knot and torsion of cord are cause by occasional factors and difficult to prevent.

脐带异常中脐带真结节、扭转均属偶然因素，难以预防。

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Objective: to determine obstetrical risk factors and pregnancy outcome of fetuses with true knot of the umbilical cord.

目的：探讨脐带真结的危险因素及其妊娠结局。

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Researchers also discovered the husband and wife who will stay true to their 'til death us do part' vow will have met through friends –and tied the knot after three and a half years together.

研究人员还发现，经朋友认识、并在交往三年半后结婚的夫妇会长相厮守。

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