Customs vary greatly _____ country to country.[ ]
A. from
B. at
C. for
D. with
答案:A
下列哪种疾病常常无骨膜反应()
A.内生软骨瘤
B.慢性化脓性骨髓炎
C.骨肉瘤
D.动脉瘤样骨囊肿
E.尤因(Ewing)肉瘤
大树的栽植