下面依次填入横线上的词语恰当的一项是（　 　）

①张教授把祖辈_________下来的秘方献给了当地的医疗部门，受到了人们的称赞。

②北海不仅__________了北部湾古老的文明，也经历了改革开放的风雨历程。

③清晨，在林间小路漫步，一阵阵_________的鸟鸣声，使我的尽情带回轻松愉快。

    Tom ____ up at 6:30 every morning and he ____ to school at 7:40. He ____ math at 8:30 and science at 9:30. English is his ____ subject. He ____ it because it's really ____. Mr. Green is his math teacher. He has ____ at 12:00 at school. His music and P.E. classes are often in the afternoon. They are ____. But he ____ not like history, because it's ____. He has seven classes on Monday, Tuesday and Thursday. He has six classes on Wednesday and Friday.

下列结构具有造血功能的是（     ）。