What caused the development of feudalism

There are traits like blood type and eye color, and others like speaking english or having a scar. what are the terms used to describe these different types of traits? how are each defined?

Brainliest to who answers! what will always cause a supply curve to shift to the left?

Which sentences describes a cycle of dependency? a. aid harms the local economy creating the need for more aid.b. aid improves infrastructure and creates more wealth and more good infrastructure.c. aid programs become more reliable over time so people can depend on them.d. no answer is correct