Mary found it hard to concentrate ……………….. her work because of the noise.Đoạn văn42/96Part 4: Questions from 51 to 55. Fill in each of the sentences with correct prepositions. Mary found it hard to concentrate ……………….. her work because of the noise. Nhập câu trả lời ở đây0/3000 ký tựGiải thíchMary found it hard to concentrate on/ upon her work because of the noise.