甲胎蛋白大部分由下列何细胞产生()
A．红细胞
B．肝细胞
C．网织红细胞
D．胎肝细胞
E．巨核细胞
参考答案：D
铸造全冠颈部肩台通常为
A．转移焊接法B．前焊接C．后焊接D．离模焊接法E．连模焊接
Tom studies harder this term. _______, he has made great progress in his lessons.
A．As a result
B．After all
C．By the way
D．Instead
