off the mark

adv. 离题的

例句与用法：

Be quick off the mark if you hear of something promising.

若听说有前途的事情要马上行动。

Local firms have been quick off the mark to cash in on the oil boom.

地方商行不失时机地利用油价暴涨大赚其钱。

You have to be quick off the mark when you answer a newspaper advertisement.

回应报纸的广告得说办就办。