Professor Smith, along with his assistants,______ on the project day and night to meet the deadline.[ ]

A. work  

B. have worked

C. is working

D. are working

男性，54岁，骨病变活检镜下见皮质骨表现为层板骨纹理结构粗糙，部分骨细胞消失，骨陷窝空虚，并可见微裂；骨髓小动脉内膜、内弹力层消失，肌层纤维化，外膜增厚。病理诊断应为（）。

A.放射性骨坏死

B.骨纤维异常增殖症

C.家族性巨颌症

D.朗格汉斯细胞组织细胞增生症

E.慢性局灶性硬化性骨髓炎