are加動詞ing是什么時態

　　We are very sad to hear that you are leaving.

　　聽說你要走了，我們十分難過。

　　Here are two records that are bubbling under.

　　這兩張唱片將會走紅。

　　What are you doing? Are you out of your mind?

　　你在干什么？你瘋了嗎？