"Who introduced the concept of reflexivity as a way to help us better understand how we participate in social systems that may help or harm ourselves or others?"

The concept was identified by sociologists William Thomas and Dorothy Swaine Thomas

Explanation:

The concept was identified by sociologists William Thomas and Dorothy Swaine Thomas. This concept circularly relates cause and effect in structures of human beliefs.

When introducing the concept they said "If men define situations as real, they are real in their consequences".

answer: 21

step-by-step explanation:

divide 630 by 30. 30 goes into 630 21 times