You are given only half an hour to finish your speech on the subject, so you'd better not _____ it too far. [ ]

A. expand    

B. extend    

C. enlarge  

D. increase

肾结核的感染途径多见于（）

A.血行感染

B.上行感染

C.淋巴感染

D.直接感染

E.接触感染