单语范例（未经PONS编辑处理）
A skein is a coil of yarn twisted into a loose knot.
en.wikipedia.org Either one of the crossbars will have a flat edge to allow the skein to slide off, or will be completely removable.
en.wikipedia.org Skein relations are often used to give a simple definition of knot polynomials.
en.wikipedia.org Depending on the knot polynomial in question, the links (or tangles) appearing in a skein relation may be oriented or unoriented.
en.wikipedia.org To do this, skeins of silk thread are immersed in large tubs of hydrogen peroxide.
en.wikipedia.org