诊断纵隔畸胎瘤的特征性CT征象是（）
A.肿块位于前上纵隔
B.肿块有分叶
C.肿块内有齿样骨化
D.肺内转移
E.以上都不是
参考答案：C
除数一定比余数大．______．
My brother gave me a present for my birthday but I gave him nothing ______ his.
A．in return
B．by turns
C．in turn
D．in return for
