The energy that can be renewed again and again is known as renewable source of energy. Example : water, sunlight, wind et cetera.
The energy cannot be created again,once destroyed is known as non renewable source of energy.
The energy obtained from coal is non-renewable.
Energy obtained from burning plant waste is renewable
Energy obtained from water spring inside the earth is renewable.
Energy obtained from natural gas is non renewable.
Out of the following given choices;
(1) an increase in the number of clams
(2) a decrease in the number of water plants
(3) an increase in the number of crabs
(4) a decrease in the number of crayfish
The answer is D. Crayfish are are freshwater crustaceans resembling small
lobsters. Clams and crabs are found in marine waters. Most crayfish cannot
tolerate polluted water. Crayfish feed on animals and plants, either living or
decomposing, and detritus, therefore a decrease in small invertebrates in the river
would decrease their food source thence
consequently affect their numbers.
