Answer:
B. Populations of amphibians in a few local areas have declined dramatically in the last few decades
Explanation:
The continuous, low-level extinction of species that has occurred throughout the World and at least six species of frogs have not been seen for one to three decades and also it has recently been discovered that some species of salamander-specific chytrid has gone into extinction
They're called Enzyme. They're made up of proteins. They act as a biological catalysts that can speed up chemical reaction. They have an active site that certain substrates binds into it and form a product. Enzyme works under optimum pH and temperature and the active sites are not changed unless denatured.
the controlled variables are, timing of adding ice, water used, and amount of sugar. the dependant variables are, daily temperature, and amount of lemon juice. the independent variable is, number of glasses sold. hope it helps
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