临到口渴时才去凿井。比喻事到临头才想办法to do nothing until the last moment; to wait until one is thirsty before digging a well

• 秀全不像有些应试之人,临渴穿井,应试之前仍捧着书本。

  Xiuquan is not like some examinees, who fail to prepare until the last moment and are still carrying books around just before the examination.