若|a|=2，|b|=6，a＞0＞b，则a+b=( )
﹣4
A．He has finished the paper.
B．He put his paper somewhere else.
C．He forgot to begin researching his paper.
D．He postponed the research.
下面这几种模塑成型工艺中，（）是加工量较低的。
A、注射成型
B、挤出成型
C、传递成型
D、浇铸成型
