______children that failure is a normal part of learning is the best way to get them perform well in school.

A．Telling

B．Being told

C．Having told

D．To tell

确诊白血病的主要依据是（）

A.贫血，发热，出血

B.肝脾淋巴结肿大

C.骨关节疼痛

D.外周血可见原始或（和）幼稚粒细胞

E.骨髓象原始细胞增生>30%