The number of the people in Nantong than in Shanghai.A. are smaller thoseB. is smaller

问题补充：

The number of the people in Nantong than in Shanghai.

A. are smaller, those

B. is smaller, those

C. is smaller, that

D. are smaller, that

答案：

A. are smaller, those

B. is smaller, those

(答案→)C. is smaller, that

D. are smaller, that

解析：句意：南通的人口数量比上海的小。此句的主语是number谓语动词要用单三。than后面的代词代替的是number, 意思是 the number in Shanghai，代替的是单数，所以要用that。故选C.