has known是什麼時態

If his patience is tried at meetings he has been known to stalk out.

大家都知道如果他在會議上失去耐心，便會憤怒離席。

Children are enthralled by his stories; he has been known to fill theatre halls in Australia.

孩子們爲他的故事所着迷；衆所周知他在澳大利亞總是場場爆滿。

The truth has become known to all.

真相大白。

Never before has he known such delight.

他從來沒有這樣快樂過。

The day after it has been known as Black Friday.

後一天被稱爲黑色星期五。