seize an opportunity;when the opportunity arises; take advantage of the occasion ? 大臣們決定～，開始變法。The ministers dicided to start the political reform as the opportunityarose.
因利乘便yīn lì chénɡ biàn
因：憑借；乘：依靠，憑借。形容憑借形勢(shì)的便利。take advantage of, seize an opportunity, take the tide at the flood