下列哪一个骨肿瘤及肿瘤样病变最好发于儿童时期的脊柱()
A.骨囊肿
B.动脉瘤样骨囊肿
C.骨嗜酸性肉芽肿
D.软骨黏液样纤维瘤
E.骨巨细胞瘤
参考答案:C
That hero who died in the war was so brave that he never ____ ____ to the enemies until death.
A.gave up
B.gave out
C.gave in
D.gave away
影响信息处理能力的内部因素主要有()、()、()、()。