How do students choose pencils?

2B pencils are used in the examination, because the machine uses infrared induction carbon technology to mark the test paper, and the data is obtained through the sensitive reaction of carbon to infrared rays. Therefore, we need to use some pencils with high hardness to answer. HB pencil is used for daily answers. It has moderate blackness and is easy to read. Moreover, the eraser is easier to erase.

Why do doctors only use blue and black pens?

Because medical records and medical orders are legal texts, it is necessary to identify the writing time in case of disputes. The blue black ink is made of ferrous tannate and blue dye, and the writing time can be determined by observing its oxidation degree.

Don't use these stationery any more!

1. Correction fluid

Also known as correction fluid. The correction liquid contains benzene, which is harmful to human body.

Hazard: excessive inhalation may cause benzene poisoning, ranging from dizziness and vomiting to nerve paralysis.

2. Scented eraser and ballpoint pen

Essence is added to the fragrance eraser and ballpoint pen. Essence contains a large amount of preservatives, boron, formaldehyde and plasticizer.

Harm: excessive inhalation will lead to headache and vomiting. If ingested carelessly, it will cause liver poisoning.

3. Ultra white Workbook

In order to make the paper look better and whiter, the defective manufacturer adds excessive fluorescent whitening agent in the production process, and can smell the pungent smell when opening the operation book.

Hazard: long term exposure and use may cause adverse effects on blood and liver, and may cause damage to vision, resulting in decreased vision.

What if the pen doesn't print?

This is because the ink at the tip of the pen is blocked by condensation. Put the pen in half a cup of warm water and let it stand for 10 minutes before taking it out to dry. It can be used again~

Proper use of post it notes

Most of the students tear the post it notes from bottom to top, but the post it notes that are torn off in this way tend to tilt up. The correct tear method is to tear it from left to right, so that the post it notes won't rise~

(WeChat official account of "广东科普科技有限公司"， to bring you more interesting information about stationery.)

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