他向观众致意，表达谢意。

He ___acknowledges the audience, showing his gratitude.

他最终承认了自己的错误。

He finally ___acknowledges his mistake.

请发送邮件后等待系统自动确认收件。

Please wait for the system to automatically ___acknowledge your email after sending.

他在颁奖典礼上感谢了家人的支持。

He ___acknowledges his family's support during the award ceremony.