Поставить в множественное число: a book- a man- a room- a student- a box- a desk- a child- a city-

books

men - исключение

rooms

students

boxes 

desks

children

cities - чередование y на i

a book-books

a man- men

a room-rooms

a student-students

a box-boxes

a desk-desks

a child-children

a city-cities