'समाजशास्त्र तेजी से बदलते सामाजिक तंत्र का अध्ययन करता है।' यह किसने कहा था?

In Sociology, the term 'norm' is defined as a:

Which one of the following correctly defines the concept of 'social structure'?

Which one of the following is NOT an essential element or basis of a 'community' in traditional sociology?