Answer:
b. A person's caste is determined by how deeply religious he is.
Explanation:
I think that the answer is, "It is the guardian of two of Islam's most sacred sites". This is because Medina and Mecca are located there, and they've very important sites in the Islamic religion.
Answer:
1. Most common causes---- Mercury, nitrogen and phosphorus, pesticides, dissolved metals (excluding mercury) and PCBs (industrial pollutant)
2. Least common causes---- pH changes
, sedimentation and hypoxia.
Explanation:
The most common heavy metals that causes pollution are chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), arsenic (As), mercury (Hg), zinc (Zn) and copper (Cu). Nitrogen and phosphorus application pollutes the water due to its leaching nature. The use of pesticides is very common in agriculture that cause more pollution. Pollutant comes from the industries cause water pollution and is responsible for a number of diseases.
