习惯包装采用某些商品销售包装的习惯（沿用）造型，属于（）。
A．便于使用的销售包装
B．便于识别的销售包装
C．便于携带的销售包装
参考答案：B
如图所示收音机上调节音量的旋钮实际上是一个 ，它是通过改变导体的 来改变电阻的．若将接线片B、C接入电路，则顺时针转动旋钮触片时，收音机的音量将变 （“大”或“小”）．
In 2000 they _____. They _____ for seven years.[ ]
A. marry, have married
B. married, have been married
C. have married , have married
