3-

1 – (two events) I prefer to study alone, writing in my computer
2 – (two events) I love to stay home, relaxing in my bed
3 – (two events) I don´t like to stand in long lines, waiting to see a movie
4 – (relative clause) In Mexico we see a lot of people speaking English
5 – (relative clause) I prefer to eat tradicional fruit growing in my farm
6 – (relative clause) children eating healthy food have less illnesses

4-

1 – In the picture, we could see people shopping at the stores.
2 – This report will be useful for those living in the north of the country.
3 – The audience stood up and clapped, he coming back to the stage.
4 – Our apartment is always full of neighbors, chatting and drinking coffee.
5 – We sat at the library, studding for the exams.
6 – I could hear the children, playing in the other room.
7 – They stayed at the club for hours, having lots of fun.