vicissitude

It reflects the vicissitude of society.

它反映了社会的变迁兴衰。

So great a vicissitude in his life could not at once be received as real.

他的生活中发生了如此巨大的变迁，他一时还无法相信是真的。

This kind of boundary is relative, only has the temporary stability and the validity, it along with situation change, but unceasing vicissitude.

这种边界是相对的，仅具有暂时的稳定性和有效性，它随着情境的变化而不断变迁。