____ nearly all behavior is learned behavior is a basic assumption of social scientists.
A、/ B、That C、It is acceptable D、When
____ nearly all behavior is learned behavior is a basic assumption of social scientists.
A、/ B、That C、It is acceptable D、When
B
根据句子的结构分析，句中的nearly all behavior is learned behavior是一个完整的句子在充当主语，称为主语从句。that引导主语从句只起连接作用，没有实际含义，但不能省略。