1. I have learned Spanish for three years.
2. My friends have difficulty in understanding Australian's accent.
3. Because of being sick, Tim didn't join the summer camp.
hoặc Because of Tim's sickness, he didn't join the summer camp.
4. When you were young, were you able to speak English?
5. Three hundred students took part in/joined in/participated in the swimming competition last year.
6. North pole is so cold that humans can't live there.
7. We last saw Barak more than six months ago.
8. I am looking forward to seeing the sights in London.
9. Can you tell me when will your plane land tomorrow?
10. Jim advised me to take part in the summer camp in Canada.