在分词作状语时，其逻辑主语一般应与句子的主语一致。如果不一致的话，分词前面可以带有自己的逻辑主语(名词或代词)，构成分词的独立结构(或称为带逻辑主语的分词结构)。分词独立结构可表示伴随情况、陪衬动作、附加说明以及表示时间、原因、条件等。 【例如】

The moon has no light of its own, only sunlight shining on it.

(附加说明)

She rushed out the room, the little baby carried in her arms.

(伴随动作)

Maggie ran back to the kitchen, eggs held carefully in her hand.

(伴随动作)

They being blind men, how could they see the elephants? ( =As they were blind men... )

(表示原因)

Circumstances changed, it is necessary for you to make a new plan.

(表示原因)

A force acting through a distance, work is done. (表示条件)

Both bright side and dark side considered, you will have the confidence to overcome this difficulty. (表示条件)

All flightsshavingsbeen cancelled because of the snowstorm, many passengers could do nothing but take the train.

there be句型和it也能引出分词独立结构，作状语修饰主句，there和it相当于分词的逻辑主语。

【例如】

There being nothing else to do, we went home.

Thereshavingsbeen no rain, the plants withered. It being impossible for most students to turn in their papers as scheduled, the teacher decided to give them another two days. The sale usually takes place outside the house, with the audience ____on benches, chairs or boxes. (CET 4 2000,1)

A)shavingsseated B) seating C) seated D)shavingsbeen seated

本题考察的是with引导的分词的独立结构，seat一般用被动形式表示主动意思，所以用过去分词，答案为C。

seat可以用于如下句中：He came in and was seated in the chair. Please come in and be seated. So many directors____, the board meeting had to be put off. (CET 4 2000,6)

A) were absent B) being absent C) been absent D) had been absent

本题考察的是分词的独立结构,主语与分词之间是主谓关系，因此选择B。