Question

21.

What percentage of water on earth's surface is readily available to terrestrial life?

Group of answer choices

97.5%

71%

5%

1%

less than 0.01%

22.

Dams can be detrimental to all of the following *EXCEPT*

Group of answer choices

fishermen

aquatic wildlife

rural and ur

Based on the use of water in an average home in the United States, which of the following methods would conserve the most water?

Group of answer choices

Decreasing the water temperature when taking a shower

Replacing old toilets with new low flow toilets

Turning the water off while brushing teeth

Drinking more bottled water instead of water from the tap

Taking baths instead of 5 minute showers

24.

Which of the following actions are people concerned about water pollution most likely to do?

Group of answer choices

Dispose of used car oil in the storm drain

Switch from organic to inorganic fertilizers

Pull weeds by hand rather than applying herbicides

Switch to a laundry detergent with high phosphate content

25.

Which of the following is NOT a water pollutant that threatens human health?

Group of answer choices

Cholera

Ozone

Mercury

E. coli

Arsenic

ban electricity customers

towns and farms upstream of the dam location

23.

Answer 1

21.percentage of water on earth's surface is readily available to terrestrial life

(e). 0.01%

Saline water in oceans, seas and saline groundwater make up about 97% of all the water on Earth. Only 2.5–2.75% is fresh water, including 1.75–2% frozen in glaciers, ice and snow, 0.5–0.75% as fresh groundwater and soil moisture, and less than 0.01% of it as surface water in lakes, swamps and rivers.

22. Dams can be detrimental to all of the following *EXCEPT* a) Fisherman

Large dams play an important role in promoting economic and social development in many countries. However, the construction of such dams can have a detrimental effect on the environment.

Large dams have led to the extinction of many fish and other aquatic species

Most rural Africans are directly dependent on surface water - rivers, wetlands, springs and lakes - for their water supply. ... A few ways that dams harm water supply include: By trapping river-borne nutrients, dams can lead to the growth of toxic algaes

Dam has its environmental impacts, however reach much further downstream in the forms of erosion, ecosystem degradation and landslides. Its social impact affect many surounding areas, namely urban centres. For example The Three Gorges Dam.

23. Based on the use of water in an average home in the United States, Replacing old toilets with new low flow toilets

Although toilets all look pretty much alike, the amount of water released by flushing varies widely from one toilet to another. Generally speaking, the older the toilet, the more water it uses. Toilets built before 1982 use 5 to 7 gallons per flush. Now, toilets are designed to flush using only 1.6 gallons of water.

24.people concerned about water pollution most likely to do Dispose of used car oil in the storm drain

Properly dispose of chemical cleaners, oils, and non-biodegradable items to keep them from ending up down the drain. . oil and gasoline that drips from millions of cars and trucks every day. should be drain

Switch from organic to inorganic fertilizers is not a good option because Over applying inorganic fertilizers can also damage your plants. Common symptoms of over fertilization include decreased growth, defoliation, wilting or plant death in extreme cases.

25. Ozone  is NOT a water pollutant that threatens human health

Ozone is a very reactive gas that can oxidise bacteria, moulds, organic material and other pollutants found in water. Using ozone to treat wastewater has many benefits: – Kills bacteria effectively. – Oxidises substances such as iron and sulphur so that they can be filtered out of the solution.

Cholera is caused by the bacterium Vibrio cholerae. People become infected after eating food or drinking water that has been contaminated by the faeces of infected persons

Arsenic contamination of groundwater is a form of groundwater pollution which is often due to naturally occurring high concentrations of arsenic in deeper levels of groundwater. It is a high-profile problem due to the use of deep tubewells for water supply ...

Mercury emitted into the air eventually settles into water or onto land where it can be washed into water. Once deposited, certain microorganisms can change it into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish.

Since E. coli is released into the environment through deposition of fecal material, this bacterium is widely used as an indicator of fecal contamination of waterways. ... coli and fecal pollution and the use of this bacterium as an indicator of fecal contamination in freshwater systems.