It is one of the funniest things_______on the lnternet so far this year.   [ ]

A. finding                    

B. being found  

C. to find                    

D. found

液平在下列哪种空洞较常见（）

A.厚壁空洞

B.薄壁空洞

C.张力性空洞

D.慢性纤维性空洞

E.急性空洞