【正文】
15. She ______ ( am, is , are ) a middle school student . 16. I ______ ( am ,is , are ) from Beijing . 17. Mary and Grace _______ ( am , is , are ) good friends . 18. There _______ ( am , is , are ) a pen in my pencil case . 19. There _______ ( am , is , are ) some apples on the table . Ⅳ 、 根據(jù)上下文完成句子。 Ⅱ 、 單 項(xiàng)選擇。 There are two workers in the room. One is old and the other is young. The young worker is the old worker’s son. But the old worker is not the young worker’s father. Why? 30. Answer:____________________