基本解释圆珠笔芯英汉例句双语例句The double-tube ball-point pen consists of a penholder, two pen heads, two pen refills and two pen caps, wherein the penholder is provided with two parallel tubes;本实用新型是由一个笔杆、两个笔头、两个笔芯和两个笔 帽组成。笔杆有两个平行的管道；ip.com