Twins, Arianne and Enyala Banks (18) from Cardiff, are celebrating today as they both win places at Oxford University. The girls, who are students at Cardiff Sixth Form College, have however chosen very different courses to study.  Arianne who gained A* in French, A* in Politics, A* in History and A* in Biology is off to study Law with French Law at Mansfield College and Enyala who gained A* in Maths, A* in Physics, A* in Chemistry and A* in…