阅读下面的材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

    Miss White comes into the classroom. She sees some school things on the teacher's desk. There is a pencil box, a red pencil, two black(pen) andorange notebook. Whose are they?

    Miss White asks Tina, "Tina, is this(you) pencil box?" Tina says，"Yes, it is. Thank you." "Are(this) your pens?" asks Miss White. "No, they. They're(Mary)," says Tina.

    Miss White goes to Mary and says, "Are these your pens, Mary?" Mary says, "Yes,are. Thank you." "Whatthe red pencil? Is it(you), too?" Miss White asks. "No, it isn't," says Mary, "I think it is Bob's, please ask(he) ."