be quick off the mark
US /bi kwɪk ɔf ðə mɑrk/
UK /bi kwɪk ɔf ðə mɑrk/

1.
反應迅速, 理解力強
to be quick to understand or respond to something
:
•
She was quick off the mark to answer the difficult question.
她反應迅速,回答了那個難題。
•
The company was quick off the mark to adapt to the new market trends.
該公司迅速適應了新的市場趨勢。