Why were mandela tutu and biko most important?

They have an international face to apartheid’s injustice

Explanation:

the answer is a. the harappan civilisation is also called the indus valley civilisation, this is because they built their cities along the indus river. the reason behind this location can be found in the rest of the "old world" civilisations like mesopotamia or egypt, the first built their cities along the rivers tigris and euphrates, the second along the nil; : their respective civilisations thrived because the overflowing of their respective rivers produced favorable conditions for agriculture, their main support.

they met to talk about what type of government they wanted and how best to go about creating that republican government.