一口答应yī kǒu dā ying

readily agree (/promise)
❍ 经理先生昨天您可是～了，您说话可要算话！Mr Manager,you readily agreed yesterday. You can’t go back on your word.

一口答应yī kǒu dā yinɡ

形容不加思索地就同意别人的意见。consent without any lengthy deliberation, readily agree, readily comply with