Memories on the Blackboard

I passed the small blackboard again and could not help stopping. There was a “9” point embedded in the “10” points which were brushed in rows, which seemed incompatible.
“9” points above, it is my name, and I, but aroused the corner of the lip…
Chemistry Test Site for Physical and Chemical Laboratory Operational Skills Examination. In front of each experimental platform stood a classmate, busy but full of success. I’m in it, too. Soon after heating, the reagents of the same group showed blue, indicating that the test was copper oxide. And my boiling several times, but still transparent. Despite all my doubts, I decided to respect the facts of the experiment and fill in the test paper with “carbon powder”.
My hunch was fulfilled. The invigilator passed my examination paper smoothly all the way. After a short stay, he made a big fork on the “carbon powder”. Immediately, she turned around and wrote “9” on the scoring board. Nine points, my physical and chemical experiment operation skills test score is only nine points, in that row of brushing “10” points, is so big and dazzling, and seems to be so insignificant…
The students around me testified that my reagent did not turn blue. Without saying a word, I quickly walked back to the experimental platform, picked up the unidentified black solid, and asked the teacher to do the experiment. The result again made me wonder. After heating for a while, the reagent showed a cheerful blue color and floated lightly in the test tube.
“I still don’t think so.” I persisted as always, and took out the dilute acid I used for the experiment. The teacher then brought the pH test paper, which turns red when acid turns red and blue when alkali turns blue, ready for final and final pronunciation test.
I held my breath, stared at the test paper, and slowly dipped into the reagent bottle, a thick blue, eager to spread, until I swallowed the whole test paper, very deep, very deep. The answer is clear. The dilute acid I used to do the experiment is alkali. I was right all along. And I never gave up.
Students felt that the “9” score on the blackboard should be changed to full score. But I just laughed and said nothing, let this “9” stay on the blackboard, because it is the result and witness of my persistence. Is it different from other “10” scores? No, 9 points. It can be as perfect as that.
“9” has survived. At the same time, the 9 points on the blackboard, the stubborn reagents that refuse to turn blue, will be engraved in my memory, constantly reminding me to insist on those that should not be given up, such as the objective facts that no one can refute.
This small blackboard and everything else will be my proudest memory, and at the same time, it will also be an inexhaustible motivation for me to go on.
The memory on the blackboard is beautiful and firm.