Choose the correct preposition . I have studied English ___ three years . a)since b)for c)in 2)I think I'm good ___English

1) I have studied English for three years.2) I think I\'m good at English. 3) I am interested in all the subjects. 4) We study in school No 115.5) There are many places of interest in my town.6) I rely greatly on my friends.7) And I care for them. 8) My penfriend lives in the country.9) I often write letters to him every month. 10) I always look forward to getting letters from him.