seize an opportunity;when the opportunity arises; take advantage of the occasion ❍ 大臣们决定～，开始变法。The ministers dicided to start the political reform as the opportunityarose.
因利乘便yīn lì chénɡ biàn
因：凭借；乘：依靠，凭借。形容凭借形势的便利。take advantage of, seize an opportunity, take the tide at the flood