The correct answer for the question that is being presented above is this one: "Schmidt-Cassegrain focus." A focal arrangement that has a thin lens that the light passes through before traveling down the tube to the objective mirror is a Schmidt-Cassegrain focus.
Here are the following choices:
a. Cassegrain focus
b. Newtonian focus
c. Schmidt-Cassegrain focus
<span>d. Schmidt focus</span>
Velocity, direction, or both at the same time.
A parachute is a device designed to generate a LOT of air resistance.
Parachutes do that very well in places where there's any air to work with.
There is no air on the Moon.
