Don't talk while having dinner(while you are having dinner)．

　　吃饭时不要说话。

　　Though working hard，he couldn't earn enough money to pay off his debt.

　　尽管努力工作，他也不能挣到足够的钱还清债务。

　　2．动词­ing形式短语前可用介词on/upon，表示"一......就......"。

　　On hearing the news，all the pupils jumped with joy.

　　一听到这个消息，所有的学生都高兴得跳了起来。

　　3．为了强调结果，可在动词­ing形式前加副词thus。

　　The bus was held up by the snowstorm，thus causing the delay.

　　公共汽车遭遇暴风雪，因此造成了延误。

　　三、动词­ing形式的否定式和完成式

　　1．动词­ing形式的否定式通常在­ing形式前加否定词not。

　　She was puzzled，not knowing what had happened.

　　她迷惑了，不知道发生了什么。

　　2．动词­ing形式的完成式表示的动作发生在谓语动词之前。

　　Having finished the letter，he folded it and put it into the envelope.

　　写完信后，他把信折起来装进了信封。

　　四、独立成分和独立主格作状语

　　有些现在分词短语可以独立成为句子成分，不受句子主语的限制，这些常见的结构有：judging from/by"从......来判断"；generally speaking"一般说来"；supposing"假设"；speaking of"说到"；considering"鉴于"。

　　现在分词作状语时，它的逻辑主语要与主句的主语相一致，但有时也可以有自己独立的逻辑主语，这种结构称为独立主格结构。

　　Ⅰ.单句语法填空 【导学号：38300012】

　　1． (know)the place very well，I acted as their guide.

　　2． (finish)his homework，the boy went out to play.

3．I built all my hopes on his promises，only (find)that he was not an honest person.