轧制过程是靠旋转的轧辊与轧件之间形成的（）将轧件拖进轧辊的辊缝的。
参考答案：摩擦力
John once worked in a remote mountain village school, which is ______ only on foot.
A．accessible
B．acceptable
C．available
D．appropriate
When the dispute over duty payment arises between the duty payer and the Customs, the duty payer should first pay the duty and then, within （） of the issuance of the duty memo, apply to the Customs in writing for a reconsideration of the case.
A. 10 days
B. 20 days
C. 30 days
D. one year
