A smile costs nothing but gives so .A. littleB. fewC. manyD. much

问题补充：

A smile costs nothing, but gives so .

A. little

B. few

C. many

D. much

答案：

A. little

B. few

C. many

(答案→)D. much

解析：so及不定代词的用法。so后可跟不定代词many和much， much指代上句中的不可数名词nothing。