What is the leading cause of water contamination in countries without water treatment plants?

Sewage

Explanation:

The leading cause of contamination in the countries without having water treatment plants is sewage. The sewage disposal is the main waste that needs to be treated.

Sewage has many harmful bacteria growing on it. This can be unhealthy if people are exposed to it. Sometimes the pipes leakage can take place infecting the nearby water bodies.

This can be a very serious issue affecting the freshwater which is used by the people for many domestic and commercial purposes.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

question: which statement best describes the different properties of metals?

answer: they are shiny and bend without breaking.

since metals have certain characteristics properties, they include the following: they are ductile, malleable, shiny, hard, lustrous, flexible and they are good conductor of heat and electricity. so therefore, metals are not dull and they are not non-flexible as listed. instead, they are shiny and flexible.

hope this , have a good day. c;