请帮忙翻译为英文 “从上午9点，他们已直在开会”

They have been in the meeting since 9:00am。
我觉得用现在完成进行时好些。

The have been (at a) meeting since 9 am

They have been in the meeting from 9 in the morning.

From nine o’clock,they had having the meeting.
应该用过去完成进行时。

they have being meeting since 9am