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 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 and dirt!