Which best describes the use of interchangeable parts in manufacturing in the 1800s?
A. Interchangeable parts were designs for the construction of mills and factories that used resources, such as water, to power the equipment.
B. Interchangeable parts were identical parts that could be exchanged for one another in the manufacture of guns, clocks, and other goods.
C. Interchangeable parts were goods that were custom-made by hand using the expertise of skilled workers.
D. Interchangeable parts were pieces of equipment that were used by factory workers to make one element of an entire machine or mechanism.

Which is one reason many african nations have not prospered after gaining independence from european colonial powers? a. colonial powers sent their weakest economic advisors to the new countries, and their recommendations were flawed. b. independence left them with weak economies, and many countries have been unable to overcome or recover from these burdens. c. the desert region of the interior is inhospitable to foreign investors, and business interests focused on the coastal mediterranean cities. d. the money endowed upon independence is still tied up in the bank of england, which is hesitant to make loans to struggling nations.