Use the prepositions to complete gaps.(at,of,by,for,in,as,on,)

 I'm archaeologist's assistent and i've been working ___ a Roman fort __ two weeks . I've always been interested ___ archeology,so when i saw the job advertisement ___the newspaper I applied immediately.I was lucky.Although i had no experiense __ working __ an crchaeologist ,I was offerd the job.so now i spend most of the day surrounded ___dust and dirt!