书画是我国最具民族性和广泛性的艺术品，中国书画拍卖又可分成（）
A.古代书画
B.近代书画
C.现代书画
D.当代在世画家书画
参考答案：A, B, C
用am, is, are填空。
1. What _____ those? _____ they birds?
2. He _____ my friend. _____ your friend a boy or a girl?
3. This _____ his ruler. Where ______ my ruler?
4. I _____ in Class Three. ______ you in Class Three,too?
5.Those ______ their apples. Where ______ his apples?
具有免疫促进作用的成分是（）
A.香豆素
B.细柱五加总皂苷
C.雷公藤春碱
D.秦艽碱甲
E.雷公藤内酯甲
