Answer: Options A, B and D.
Explanation: shields are layers of old rocks that metamorphosed as a result of mountain-building events. Shields also have sedimentary layers that usually rest on the lava of the rock.
<span>His opportunity cost is to give up the next best thing, in this case the digital camera. It is called a trade-off between cell phone and digital camera. But I could not imagine that it is a big one, compared to efficiency and equality.</span>
The answer to the question is B
B.rely on wind power rather than electricity
