She was surprised by his quick answer to the problem.

她对他迅速回答这个问题感到惊讶。

He promised me a quick answer.

他答应我从速答复.

E. g. He gave a quick answer to the question.

他迅速地回答了问题。

No one in the office promised a quick answer to the matter.

办公室没人答应对此事从速作答.