Though different body movements mean different things in different cultures, ______smile

is ______ accepted as a sign of happiness or being friendly.     [ ]

A. the ; universally  

B. the; usually  

C. a; globally  

D. a; universal

如图是我国古代杰出的科学家。他的主要科学成就是

A．改进造纸术

B．发明指南针

C．写成《伤寒杂病论》

D．发明活字印刷术