As a new driver, I have to practice _________the car in my small garage again and again.    [ ]

A．to walk            

B．walking        

C. walked              

D. having walked  

放射治疗不能控制或改善下列支气管肺癌并发症的是（）.

A.支气管阻塞引起的呼吸困难

B.转移性骨痛

C.脑转移引起的颅内压增高

D.全血细胞减少

E.肥大性肺性骨关节病