Поставьте артикли a/an или the, где это необходимо:
1) Where id your friend? He is in ... room.
2) Jane is ... factory worker, and Ben is ... engineer.
3) Open your books at ... page ten and read ... texr nine, please.
4) Please, don't go ... there.
[!] Места для артиклей выделены многоточием.