区域性配送中心的货物配送批量比较大，而批次较小（）
参考答案：对
When I entered the classroom, I saw Mary ______ at the desk and ______ a letter.
A．seating; writing
B．seated; wrote
C．sitting; wrote
D．seated; writing
对烤瓷合金的性能要求，不正确的是
A．弹性模最低
B．机械强度好
C．铸造性能好
D．收缩变形小
E．湿润性好
