1. When reading a book, he usually takes notes.
2. Having read the text, we shall discuss it.
3. While answering to questions, he made a few mistakes.
4. After answering the teacher's questions, we started to translate the new text.
5. Being a good conductor of electricity, copper is widely used in industries.
6. Seeing the green light, we crossed the street.
7. While buying a newspaper, he lost his money.
8. Having bought a newspaper, he headed for the subway.