Understanding the cultural habits of another nation especially containing as many differ

问题补充：

Understanding the cultural habits of another nation, especially containing as many different subcultures as the United States, is very difficult.

A. one

B. that

C. some

D. the one

答案：

(答案→)A. one

B. that

C. some

D. the one

解析：句意：要了解一个国家的文化习惯，尤其是像美国这样一个集成了多种文化的国家的文化，是很困难的。这里整个句子的主语是Understanding the cultural habits of another nation，这里one是nation的同位语，这里是泛指，所以前面不用加定冠词，故选A。