People have wondered for a long time how their personalities，and behaviors are formed. It is not easy to explain why one person is intelligent and another is not，or why one is cooperative and another is competitive.

· 词的处理 ·

wonder vt. 怀疑;想知道

personality n. 个性;品格

behavior n. 行为

form vt. 形成

intelligent adj. 智能的;聪明的

cooperative adj. 合作的

competitive adj. 竞争的;有竞争心的

· 句子翻译分析 ·

People have wondered for a long time how their personalities，and behaviors are formed. It is not easy to explain why one person is intelligent and another is not，or why one is cooperative and another is competitive.

译：长期以来，人们一直想知道他们的性格特征和行为模式是怎样形成的。(人们)很难解释一个聪明而另一个人愚蠢的原因，或者也很难解释一个人有协作精神，而另一个人喜欢竞争的原因。

1. 首句主干：people have wondered how their personalities, and behaviors are formed. 修饰成分：for a long time 修饰谓语动词 wonder

2. 二句主干：it is not easy to explain why … or why …;其中，it为形式主语，to explain …为真正主语，两个why分别引导explain的两个宾语从句。

3. it is not easy to do sth. 可译为无主语句，即“很难解释”也可以添加主语，译为“人们很难解释”。