We are about to begin our descent into Los Angeles.
飞机即将降临洛杉矶机场。
----------------------------------------------------------------------
Be about to do sth.意思是“即将，正要”做某事，相当于be going to do sth.
例：
He received the telegraph from his mother as he was about to start.
他正要动身的时候接到了母亲的电报。