Recently, erasable pens are very popular in our class. Everyone uses them to take notes, write homework and take exams. Why? It is nothing more than that the words written by it can be erased with the "eraser" behind the pen! However, no matter how good things are, there will be flaws! No, a classmate in the front row of mine used an erasable pen to write during the exam, which is nothing, but when he wiped the back of the test paper, he also erased the words on the front, and he didn't find it, so he was deducted 3 points for nothing. Points of injustice. You say this is so annoying! If it were me, I would be so angry that I would vomit blood! Then I thought, the erasable pen can be erased because of the heat generated by friction. If the erasable writing will disappear when it is very hot, will the writing be completely restored when it is cold? So, I started the experiment when I got home: first write my name on a piece of white paper, erase it, then write my class on the erased name, and then put the paper in the refrigerator to freeze. After about five minutes, I took out the paper and found that all the words I wrote before appeared, and the name and class overlapped together. This is not enough, I took another piece of paper, wrote my name on it again, then poured the freshly boiled 100-degree boiling water into a transparent plastic cup, and then put the plastic cup on the words. After about four minutes, the words on the paper gradually disappeared. As it turns out, my guess was right! After this experiment, I almost never use erasable pens again. I always use non-erasable pens to write notes, homework and exams. Otherwise, if one is not careful, the consequences will be... So, I personally think that it is better to use less erasable pens in learning! Or else...you get it!