If you are going to stay in the United States for longer than a(n) ______ visit, you may be interested in

learning more about its people and culture.[ ]

A. formal      

B. regular

C. brief    

D. unexpected

关于刑法的渊源说法正确的有( )

A．新刑法典生效后，原有的单行刑法就失去效力

B．我国目前尚无有效的附属刑法

C．民族自治地方对刑法典做的变通或补充规定也属于刑法的渊源

D．刑法修正案也是刑法的渊源之一