—Mom, _____I watch TV?     

—Yes, you can. But you have to finish the homework first.     [ ]

A. must

B. could

C. will

D. need

某患者因舌根部肿瘤而行放射治疗，放疗后可能发生的口腔改变是（）

A.口干

B.牙齿龋坏

C.口腔黏膜炎症

D.皮肤发红、变黑

E.以上均是