Answer: b. burning fossil fuels
Explanation:
Free electrons seem to travel via the conductors with a certain degree of friction, or opposition to the motion. This opposition to the motion is more precisely known as resistance.
The amount of the current in a circuit relies on the concentration of voltage accessible to encourage the electrons, and also the amount of resistance in the circuit to oppose the flow of electron. Resistance to the flow of electrons in a conductor causes a loss of energy in the form of heat.
Some <u>birds</u> are both primary consumers and secondary consumers.
<u>Explanation:</u>
Primary consumers are the class of animals that are feeding upon the producers as their primary food. Secondary consumers are the class of animals that are feeding upon a primary consumer to feed themselves.
Some of the birds like sparrow, humming birds etc feed on fruits and seeds of plants to maintain their lives. They are thus the primary consumers. Others like eagle, crow eats on flesh of primary consumers. So they are secondary consumers. Thus birds can be both primary consumers and secondary consumers.
