Dos to prevent sway back posture. Sit deep in your chair, with your back straight and your chin facing ahead.train quad muscles with the correct exercises, such as half squats. Strengthen your lower abdominal muscles with leg lifts and reverse crunches.
That is the difference between the two, I am not good at explaining these types of things! XD
D is the answer, viruses can not be cure by antibiotics. Bacteria can.
