头颈部肿瘤的病理类型有（）。

A.恶性黑色素瘤

B.黏液表皮样癌

C.腺样囊性癌

D.鳞状细胞癌

E.基底细胞癌

—I don't know ______  to play the violin. 

—My cousin can teach you.[ ]

A. how  

B. who

C. what  

D. when