Do you want a pen or a ball-pen?

你是想要钢笔还是圆珠笔？

I'd like to see your new ball-pen.

我想看一看你的新圆珠笔。

This ball-pen is red.

这支圆珠笔是红色的。

I want a ball-pen and some exercise books.

请给我圆珠笔和练习本。

He rooted about in all his drawers and found the lost ball-pen at last.

他在所有的抽屉里翻来翻去，最后终于找到了丢失的圆珠笔。