Cyanobacteria or simply known as blue-green algae may have formed the oxygen into the early atmosphere. This is because these micro-organism has the capability to photosynthesize wherein they can produce oxygen and carbohydrates. In fact, all the plants contribute in the fomation of oxygen.
For an unconscious child who is choking, the best goal is to remove the foreign object that obstructs the airpath of the system. The basic steps to be performed during basic rescue are as follows: (1) <span>Perform finger sweep (2) attempt rescue breathing (3) perform abdominal thrusts. these steps are done until successful</span>
Most likely A from my point of view
