哪种类型肺癌对放射治疗最为敏感（）
A.腺癌
B.鳞状上皮细胞癌
C.未分化癌
D.肺泡癌
E.类癌
参考答案：C
Peter graduated from university in 1998. He ____ in a high school ever since.
A．works
B．is working
C．worked
D．has worked
幼儿期的思维特点？
