The answer you're looking for is D, The direct exchange of one set of goods or services for another
Yes. Source D is more believable because Source C is from a book that “Criticizes the building of the dam”. It is only a comment by a journalist and source D is information that was released by the Chinese government itself. Source D also gives a more detailed explanation about what will happen because of the project.
Social Inequality is what i think it is
Bronze is a homogeneous mixture. (In this case its two metals.)
The Social Security Administration (SSA)
