第26题: [单项选择]______ nearly all behavior is learned behavior is a basic assumption (假设) of social scientists. A. / B. That C. It is acceptable D. When 参考答案:B 答案解析:[考点] 主语从句 [解析] 通过分析句子结构可以判断,句子谓语是第二个is,表语是a basic assumption,则is前的部分在主句中起主语作用,故为一个主语从句;并且空格部分在从