A proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence. ... Most factors are held constant in a scientific experiment because you can only change one factor in an experiment so if you notice something, you'll know what caused it.
The heat can cause the killing of the bacteria. It is estimated that all the pathogenic bacteria are killed after a heating of 70-75 degree Celsius or 165 degree Fahrenheit.
The ground meat or poultry can be infected from many type of bacteria, which are present in atmosphere or in the body of the organism, whose meat is being consumed.
So, in order to kill the pathogenic bacteria, the cooking at 165 degree Fahrenheit or above for sometime must be done
So, the given blank can be filled with 165.