Homosapians started to use tools.
The number of electrons of a neutral atom always equals the number of protons.
The presence of algae is the characteristic of the photic zone of a freshwater ecosystem
The correct strategy for training for a specific running distance is to periodically (once a week or so) run that distance as a training run. This is what runners will refer to as a weekly 'long run'. This allows your body to adapt to the greater distance. At the same time, it is important that these long distances are interspersed with shorter and faster runs, as running long distances constantly can cause chronic injuries and tends to make runners slower.