春秋时期，促使社会生产力有很大发展的主要原因有（）和（）的出现和使用
参考答案：铁器农具；牛耕
The basketball coach，as well as his team，________ interviewed shortly after the match for their outstanding performance. (2012·陕西，12)
A．were
B．was
C．is
D．are
性状鉴别
