that economic rela- tionships are also social relationships in that they presuppose a definite social, political, cultural and legal con
Again, economic relationship is also social relationship in Marx's eyes. Because both relationships co-exist.
In Marx's idea, superstructure is the base for other infrastructure, all ideas rely on superstructure. Superstructure can be looked at as the foundation.
'economic activity' always includes work or labour as a set of social relationship
In Marx's social relationship of production, Marx always include that social is also a part of economic activity. Marx pointed out what differentiate human from animals are that human feel the need to work together and make the things they need to survive, and as a result of this, social relationship became essential in our lives.