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

1.
反应迅速, 理解力强
to be quick to understand or respond to something
:
•
She was quick off the mark to answer the difficult question.
她反应迅速,回答了那个难题。
•
The company was quick off the mark to adapt to the new market trends.
该公司迅速适应了新的市场趋势。