Pretty sure it is a population
Arachnids are spiders,
spiders have 8 legs,
a pair is 2,
so, arachnids have 4 pairs of legs.
Answer:
The atmospheric pressure goes on decreasing as we go up above the sea-level. Therefore, the amount of oxygen also decreases at higher altitude. Due to this reason, mountaineers carry oxygen cylinders with them, while climbing high mountains
Explanation:
