An informal meeting usually takes place on the spur of the moment to discuss a special point.非正式会议，通常都是为了讨论某个特殊问题而当场召开的。
On the spur of the moment I decided to loan my sofa and my rug to my niece who was moving to a larger home.我不假思索地就决定把我的沙发和我的小地毯借给我的侄女，她就要搬到一个较大的家了。