Look! There are so many eating grass on the hill. 　　A. horseB. cowC. rabbitD. sheep

问题补充：

Look! There are so many eating grass on the hill.

A. horse

B. cow

C. rabbit

D. sheep

答案：

A. horse

B. cow

C. rabbit

(答案→)D. sheep

解析：句意：看！这有许多羊在山上吃草。分析前面有many后接可数名词复数，选项中只前三项中都是名词单数，第四项sheep是单数与复数同行的名词。故选D