— Who should be responsible for the accident?

— The boss, not the workers. They just carry the orders _____. [ ]

A. as told

B. as are told

C. as telling

D. as they told

有关尤因肉瘤，下列说法错误的是（）

A.起源于骨髓的间充质细胞的恶性骨肿瘤

B.好发于儿童

C.好发部位为股骨、胫骨、腓骨、肩胛骨

D.X线表现为"葱皮状"

E.对放疗、化疗敏感，预后较好