With our knowledge ________ practice, we can make contributions to our society. [ ]

A. to base on  

B. basing on

C. based on  

D. base on

除哪种疾病外，均可出现纵隔增宽表现（）

A.胸主动脉瘤

B.纵隔脓肿

C.纵隔血肿

D.慢性纤维空洞型肺结核

E.纵隔肿瘤