这是一只白色的绵羊。

如图所示的工具中属于费力杠杆的一组是（   ）

When does your father go to work every day?

____

Fanny and Benny live in the ____ estate. They go to school ____ every morning. They are good friends. But they have ____ hobbies. Fanny usually reads books at home in his spare time, and Benny likes bicycling.

骨髓移植能够治疗再生障碍性贫血，是因为健康人骨髓中的造血干细胞能不断产生新的血细胞。左图为造血干细胞产生三种血细胞的示意图，上图为某正常人的血涂片示意图，甲、乙、丙为血细胞。在下列相关叙述中错误的是（   ）