Write a summary of the text in four to six sentences.
Early humans didn’t know how to keep food but now there are many ways to keep food fresh/eatable/edible.
Early hunters kept meat in cool or dried to keep it for a long time without knowing what bacteria do to their food.
Farmers found various ways to keep meat and vegetables fresh by using salt, oil, vinegar, or smoking.
New ways of preserving foods have been developed since the 19th century, such as canning, boiling and sealing, refrigerating or freezing.
Now there are a whole variety of foods that are kept fresh to eat.