that是什麼句式 hearing

1、Hearing that she agreed to stay， his grip on her slackened.聽到她同意留下，他抓着她的手放鬆了。

2、Hearing that there was an emergency case， the doctor put down his chopsticks and left at once.聽説有急診，醫生撂下筷子就走。

3、On hearing that the new novel was published， he rushed at once to the bookshop for a copy.聽説那本小説出版了，他就迫不及待地跑到書店去買。