Cara and Ben are twins . They are ten. This is their room. It's a nice room. Two beds are in the room. The yellow bed is Cara's and that green one is Ben's. The twins have one desk and two chairs . Cara's English book is on his bed. Ben's CD is on his chair. Their clock and pencil boxes are on the desk . Their schoolbags are on the chairs. Cara's English book is   _  .
onherbed onBen'sbed onthechair onthedesk