We would like to take this opportunity to thank our partners, without ________ we would not be

able to organise the music festival.  [      ]

A. whom  

B. that

C. whose  

D. who

以咽鼓管阻塞、感染和免疫反应为主要病因的是（）.

A.分泌性中耳炎

B.化脓性中耳炎

C.分泌性内耳炎

D.化脓性内耳炎

E.分泌性外耳炎