一排7个座位,甲、乙两人就座,要求甲与乙之间至少有一个空位,则不同的坐法种数是()
A:30
B:28
C:42
D:16
生物进化的规律.
A
Name
From
Hobby(爱好)
Father
Mother
Lucy
England
Playing tennis
Paul, a policeman
Sara, a worker
Mike
America
Writing
Tim, a driver
Susan, a teacher
Chen Yao
Beijing, China
Drawing
Chen Wei, a teacher
Wang Mengyi, a hotel manager
Liu Ming
Weifang, China
Playing basketball
Liu Guangfu, a doctor
Lin Fang, a worker
下图表示淀粉、脂肪和蛋白质在消化道中各部位(依次用A、B、C、D、E表示)被消化的程度。请根据图回答下列问题:
(1) (2)(3)