40MnB
参考答案：
合金调质钢，含碳量万分之40，含Mn、B均1%左右。
________ his lessons , he failed in the exam.
A．Not reviewing
B．Having not reviewed
C．Not reviewed
D．Not having reviewed
男，43岁，右颈部扪及一包块，CT如图所示，应诊断为（）
A.甲状腺腺瘤
B.甲状腺腺癌
C.结节性甲状腺肿
D.甲状腺原发淋巴瘤
E.甲状腺转移癌
