门铃叮咚响了两声，我知道有客人来了。

The doorbell made a ___ding-dong sound twice, signaling a visitor's arrival.

他们在会议上为项目方案展开了激烈的争论。

They had a heated ___ding-dong about the project plan during the meeting.

别像个傻瓜一样站在那里，快来帮忙！

Don't stand there like a ___ding-dong, come and help!