Write a program that uses key events to make a circle larger and smaller.

The correct answer is b, social stratification is needed for a society to exist. marxist theory regarding social stratification is that due to the differing economic capacities among people in society, a natural separation occurs between those that own the means of production and those that sell their labour in the production chain. 

For the sat there is a reading test, math test, and a writing and language test. the act has social studies and science tests.