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.
<span>Along North American coasts, the algae responsible for formation of kelp-beds is Brown Algae. The brown algae (such as seaweed) forms an important part of the ecosystem in marine environments as both a food source and habitat. The formation and structure of the brown algae varies from environment, kelp beds and forests are harvested for human consumption.</span>
Non-critical thinking appears to be more benifentail to the individual in education.
Nitrogen released from dead matter goes into soil, helping/feeding the plants, who in turn give us oxygen