单选题 What is the main point of the passage?

A、 Directness is characteristic of American speech.
B、 Indirectness is the rule in parts of the Far East.
C、 One should learn the unwritten rules of the speech in a culture in order to understand the people.
D、 It's important to use formal and informal speech in daily conversation.

【正确答案】 C

【答案解析】主旨题。答案C是整篇文章的论点，而其他选项是支持这一论点的论据。