The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
Body composition is used to describe the percentages of fat, bone, water and muscle in human bodies.
hope this helps x
can i have brainliest if it is right? xx
