Over a millions of years of animals and plants being crushed down in the ground<span />
Answer:
White blood cells.
Explanation:
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.
Answer:
luteinizing hormone.(LH).
Explanation:
Luteinizing hormone specially stimulates cells in the seminiferous tubules to particularly secrete testosterone, which has a role in sperm production and developing male secondary sex characteristics.
