We cannot drink water and water can damage the ecosystem. Water pollution can be reduced by adding filters to rivers.
Answer:
For the first question, choose the option in which the practice would help in the preservation of nature, for example, by reducing pollution and waste, as well as protecting areas of wildlife from getting eradicated. For example, recycling would be a sustainable practice, in which you reuse hard-to-dispose man-made-materials.
For the second question, invasive species are dangerous to an environment, for they destroy the fragile original ecosystem. They generally would destroy one or more levels of the ecosystem, resulting in a total-reduction of the populations in each language, or else an imploding boom of a certain population that would soon strangle itself out from lack of resources.
~
The body's chemical buffer system consists of three individual buffers: the carbonate/carbonic acid buffer, the phosphate buffer and the buffering of plasma proteins. While the third buffer is the most plentiful, the first is usually considered the most important since it is coupled to the respiratory system.
Carbonic acid (H2CO3) is a weak acid and is therefore in equilibrium with bicarbonate (HCO3-) in solution. When significant amounts of both carbonic acid and bicarbonate are present, a buffer is formed. This buffer system can be written as:
H2CO3 + H2O  H3O+ + HCO3-
Under normal circumstances there is much more bicarbonate present than carbonic acid (the ratio is approximately 20:1). As normal metabolism produces more acids than bases, this is consistent with the body's needs. The blood, with its high base concentration, is able to neutralize the metabolic acids produced. Since relatively small amounts of metabolic bases are produced, the carbonic acid concentration in the blood can be lower.
Since carbonic acid is not stable in aqueous solutions some of it decomposes to form carbon dioxide and water. The respiratory system is responsible for removing the carbon dioxide.
H2CO3  H2O + CO2
By combining the two reactions of carbonic acid we can write:
Answer:
Independent variable: Type of battery
Dependent variable: Time the clock stopped
Control: None for this experiment
Constants: Same type of clock
Explanation:
Independent variable in an experiment refers to the variable which the experimenter changes or manipulates in order to bring about a measurable response. In this case, the independent variable is the TYPE OF BATTERY USED.
Dependent variable is the variable that responds to changes made to the independent variable. It is the measured variable in an experiment. In this case, the dependent variable is the TIME THE CLOCK STOPPED FOR EACH BATTERY
Control is the group that does not receive the experimental treatment. In this case, NO control group is USED.
Constant is the variable that the experimenter keeps unchanged throughout the experiment for all groups. The constant in this experiment is the CLOCK USED.