`\text{Exercise 5:}` 

1. A friend of mine has come back from UK after a long vacation.

2. Hundered of people will join the carnival in Rio de Janeiro next month.

3. Last year, I went on a expedition to North Pole.

4. I hope I can visit the longest river in Europe, Voyga, in the future.

5. People used to believe that the Sun and all the stars orbit arounf the earth.

6. I often pay a visit to the local museum on Sunday.

7. Mary has taken care of all the members of our team since we set up for London.

8. I have always wanted to clinb the Mount Everest since I was a boy.

Ex 5: 1, A friend of mine has come back from UK after a long vacation

2, Hundered of people will join the carnival in Rio de Janeiro next month

3, Last year, I went on a expedition to North Pole

4, I hope I can visit the longest river in Europe, Voyga, in the future

5, People used to believe that the Sun and all the stars orbit arounf the earth

6, I often pay a visit to the local museum on Sunday

7, Mary has taken care of all the members of our team since we set up for London

8, I have always wanted to clinb the Mount Everest since I was a boy