Which of the following can NOT be used as subject?
A. Mary
B. walking along the street
C. they
D. feed the animals
网友回答
A. Mary
B. walking along the street
C. they
(答案→)D. feed the animals
解析：一般作为主题时，要用名词，代词或相当于名词的词来修饰，而ABC都是相当于名词的词，或代词，故选答案为D，D为动词词组。