The astronauts found that ______ the spaceship went further and further into space, it became more and more difficult to control its own movements.

A．if

B．till

C．as

D．while

患者男性，17岁，因左下肢疼痛3个月入院；查体：左小腿中段局部肿胀，组织增厚较硬，有压痛，局部皮温稍高。体温38．2℃，实验室检查：WBC：13．8×10¹²／L，N：78%；X线平片见下图。

根据以上临床资料及影像学检查，需要考虑哪些疾病（）

A.急性骨髓炎

B.转移性神经母细胞瘤

C.骨干结核

D.尤因肉瘤

E.骨髓瘤

F.骨肉瘤