Zach listed the process of how laser beams are produced with crystals.

a flashlamp pumps energy through the crystal.
atoms in the crystal absorb and then release some of the energy as light.
light bounces off mirrors and occasionally bounces off crystal atoms, increasing in energy.
some light escapes the tube through the highly reflective mirror, forming a concentrated beam.
which best describes zach’s error?

the crystal pumps energy through the flashlamp; the flashlamp does not pump energy through the crystal.
the atoms in the crystal do not release energy; they only absorb energy.
light does not bounce off mirrors; it focuses through glass lenses.
light escapes through the partially reflective mirror, not the highly reflective mirror.

I think that the answer is D, not certain though.

D (Uses a convex eyepiece lens)

Explanation:

no simpler subs form complex ones. synthesise = make

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day