SE机的供纸装置()的作用除了对卷烟纸进行牵引外,还能自动调整印刷后的印迹相对于烟支切口的位置变化。
A.补偿辊
B.第一张紧辊
C.第二张紧辊
D.凸轮
参考答案:C
One of the greatest benefits of stamp-collecting is that they are based on common interests,________ appearance,age or wealth.
A.other than
B.or rather
C.rather than
D.instead
处理CO2污染时,若pH值过低应加()。
A、CaSO4
B、Na2SO4
C、NaOH
D、Ca(OH)2