Which remains an unsolved challenge presented by extracting oil from oil sands in Alberta, Canada? A. how to make the process cost effective

B. how to determine precisely where to drill

C. how to avoid environmental damage

D. how to use the resources after they are removed

Answeroil-shale;

i didn’t understand your question but archipelagos are groups of island hope this

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!