1. 充当句子的状语。
2. 有自己的主语，同句子的主语不一致。
3. 名词(代词，形容词，副词，介词)+ 分词4. With + 名词 (代词) + 分词 (形容词)
例：a) It being raining, I decided to stay at home.
b) Speech having been delivered, discussion started.
c) he entered the room, with his hands open(holding a rifle).
真题剖析
(1995) 45 cliffs no longer crumbling, the beaches are 46 of the material which would 47 feed them.
45. A. For
B. As
C. With
D. Because
练习：
Do what you need to do to keep the wolf __7__ from the door, the world __8__ your thesis adviser, team leader, or laboratory director. Then use the rest of your time, perhaps at night or on the weekends, to do __9__ you really want to do.
8. A. is
B. having
C. being
D. be