BBC news 2011-02-20 加文本

1.Witnesses have told the BBC that Libyan troops have opened fire with machine guns and larger-calibre weapons on anti-government protesters in the city of Benghazi, killing a number of people.

killing现在分词作结果状语

现在分词或分词短语做状语时,也可以表示时间、原因、结果、 条件、让步、方式、伴随状况等.其逻辑主语必须和句子的主语一致,有时withwithout +名词或代词宾格+分词也可以表示伴随状况如:

While reading the book, he nodded from time to time. (时间)

The teacher stood there surrounded by the students. (方式)

He sent me an e-mail, hoping to get further information.(伴随)

分词作时间状语，如果先与主动词的动作，且强调先后， 要用having done。如:

Having answered the letter, she went on to listen to the radio.

Having been criticized by the teacher, Li Ming gave up smoking.

注意:如果是否定句,not 一般放在句首,如:
Not having received his reply, he decided to write again.

分词做状语时有时可在其前面加上while、when 、if 、even if 、although 、once、 unless等连词,使用何种分词仍然取决于与主语的关系,主动关系用现在分词,被动关系用过去分词.如:

While staying in Beijing , I visited some of my friends.

Unless invited, I will not attend his party.

Although working very hard, he couldn't satisfy his boss.