Was the weather nice?______,It was cold and windy every day.[ ]

A. Yes. it is    

B. No, it isn't

C. Yes, it was    

D. No,  it wasn 't

男，15岁，头昏乏力，牙龈出血半年，体检贫血貌，皮肤可见散在淤点，肝脾淋巴结不大，怀疑为再生障碍性贫血。下列何项最有助于诊断（）

A.周围全血细胞减少

B.网织红细胞计数减低

C.正常细胞性贫血

D.骨髓增生低下，造血细胞减少，非造血细胞增多

E.骨髓细胞培养集落生长能力降低