“Cambridge was always my dream,” says 17-year-old Hridita Rahman Khan, one of 41 students at Brampton Manor academy in east London to have won offers from Oxbridge this week. Khan’s parents are from Bangladesh, she grew up in Italy and arrived in London at the age of 14 with little English. Three years later she has been offered a place to study engineering at the University of Cambridge. Her story is one of extraordinary achievement, but there are many at…