单选题 When the author uses the phrase "eager to mix socially", he means______.

【正确答案】 A
【答案解析】词汇语义题。根据eager to mix socially的上下文:Since the opposite of shy is friendly,or eager to mix socially,可知eager to mix socially与friendly同义,都是 shy的反义词,所以正确答案为选项A。