Try to spend  your time just on the things you find  ____  .    [ ]

A. worthing doing them    

B. worth being done    

C. worthy to being done    

D. worthy of being done

应设置防撞舱壁，该舱壁应水密延伸至舱壁甲板。该舱壁应位于距首垂线不小于0.05L或10m（取小者），除可经主管机关允许外，不大于0.08L或0.05L+3m（取大者）处。