Which of the following relationships is symbiotic?
A. A male bluebird and a female bluebird provide care for their offspring.
B. A bee pollinates a flower while feeding on the flower’s nectar .
C. A tick latches on to the body of a dog and feeds on the dog’s blood.
D. A group of ants work together to build an underground nest.
E. A remora attaches to the body of a shark and feeds on scraps when the shark eats.
F. Two male red-winged blackbirds fight over territory.

Suppose that an electromagnetic wave which is linearly polarized along the x−axis is propagating in vacuum along the z−axis. the wave is incident on a conductor which is placed at z > 0 region of the space. the conductor has conductivity σ, magnetic permeability µ and electric permittivity ε. (a) find the characteristic time for the free charge density which dissipates at the conductor. (b) write the maxwell equations and derive the wave equation for a plane wave propagating in a conductor. (c) find the attenuation distance at which the incident amplitude reduces to e ^−1 of its initial value. (d) find the electric and magnetic fields inside the conductor. 8 (e) find the power loss per area of the incident electromagnetic wave at the surface of conductor.

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

The material that keeps its new shape after it is stretched is called?