pencil lead造句

1、The pencil lead is broken.
铅笔芯断了。

2、A discovery made from pencil lead is promising to change the future of the electronics industry.
科学家一项从铅笔芯中作出的发现，势必将改变电子产业的未来。

3、Do you think pencil lead will wash out of this white shirt?
你认为铅笔痕能从这件白衬衫上洗去吗？