Ink can be pretty tough to get out, but most ballpoint pen ink stains come out with lots of persistence and patience.
墨迹很难清除，不过，只要有足够的恒心与耐心，大部分圆珠笔印迹都是可以清除的。
I changed the ink cartridges in my ballpoint pen.
我换了圆珠笔里的墨水芯。
Every red ballpoint pen was distinguished with others on account of difference in quantity of ink components.
我们还根据不同厂家不同品牌的笔所添加的油墨染料的配比的不同，对红色圆珠笔进一步分类。
Every red ballpoint pen was distinguished with others on account of difference in quantity of ink components.
我们还根据不同厂家不同品牌的笔所添加的油墨染料的配比的不同，对红色圆珠笔进一步分类。
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