n.突然；唐突
The abruptness of her appearance at the meeting surprised us all. 她在会议上的突然出现使我们都吃了一惊。
Events are developing so swiftly that many feel the abruptness of the change and the need to learn anew. 事变是发展得这样快，以至使很多人感到突然，感到要重新学习。
