Pencil trivia:Refill is not lead, is it true?
The pencil is not made of lead, it is made of graphite as the main raw material. Graphite…
Dangerous trivia:Lead, the most dangerous substance on earth
It is estimated that 26 million people are threatened by lead pollution. Lead is a heavy metal that…
Pencil trivia:Is the pencil refill not lead?
In ancient times, people used charcoal, clods, etc. to mark on the stone very early in order to…