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Answer:
Formaldehyde is a highly reactive molecule that can be directly irritating to tissues with which it comes into contact. Human and animal studies indicate that formaldehyde, at certain exposure levels, can be irritating to the upper respiratory tract and eyes with inhalation exposure, to the skin with dermal exposure, and to the gastrointestinal tract with oral exposure. Formaldehyde-induced noncancer and cancer effects appear to occur only at portals-of-entry (i.e., upper respiratory tract, gastrointestinal tract, and skin).
This question can have many answers but ill try to answer it in the north slaves werent profitable so most northerners didnt have slaves and eventually slavery was seen as morally wrong in the north so in the south once abraham lincoln became president the south became its own coutry and the civil war began so after the north won slavery was abolished in the south.
Was a bloody and useless war ended nothing solders were on drugs and super sick and tired.