This is one of the best films _______.

A．that have been shown this year

B．that have shown

C．that has been shown this year

D．that you talked

草履虫收集和排出体内多余水分和含氮废物的结构是      (    )

A．食物泡和胞肛

B．口沟和胞肛

C．收集管和伸缩泡

D．表膜和胞肛