Some of the rubbish such as food paper and iron away over a long period of time.A. rot

问题补充：

Some of the rubbish, such as food, paper and iron, away over a long period of time.

A. rot

B. rots

C. is rotting

D. are rotted

答案：

A. rot

(答案→)B. rots

C. is rotting

D. are rotted

解析：句子的主干是：Some of the rubbish away over a long period of time. rubbish是不可数名词,谓语动词用单数.