现在分词作状语 (表示动作发生的时间、原因、结果、条件、让步、方式或伴随情况,通常相当于一个状语从句或并列分句。一般说来,这种结构的逻辑主语就是句子的主语。)
可以放句首的,例如:
Having eaten his dinner, the boy rushed out.
Not knowing her address, I can't write to her.
Taking the path that leads out of the town, you will come to a lake.
Hearing their teacher's voice, the pupils stopped talking at once.
Having lived with the girl for 5 years, we all know her very well.
Turning to the left, you will find the path leading to the park.
Working hard, you'll succeed.
Having received his letter, I decided to write back.
Having eaten too much, he couldn’t go to sleep
Working so hard, he failed again.