Answer:
Each objective lens has a different magnification. Multiply the magnification of the eyepiece by the magnification of the objective lens to produce total magnification. For example, a 10X ocular lens and a 40X objective lens will produce a total magnification of 400X (10 x 40 = 400).
Answer:
to avoid mutations and other issues that may occur
1 you run out of fuel 2 it takes a long time 3 it’s hard to get back 4 the conditions are constantly changing making it harder to predict what could happen. Look at Apollo 12 as a example