Which presidential action is an example of the
use of the unwritten constitution?
(1) signing a law passed by congress
(2) calling a meeting of the cabinet
(3) ordering the navy to patrol the persian gulf
(4) nominating a federal court judge

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.