Its really hard but its science pls help

What part did glaciers play in forming the great lakes?

This phrase from the declaration of independence and its primary author thomas jefferson can be used to justify which statement? a) jefferson thought this document could be used in his defense were he put on trial for treason. b) jefferson knew that the colonists' actions would have an international impact. c) jefferson believed that a bill of rights was necessary in the new government. d) jefferson was trying to show the king that the colonists were intellectuals.

Can you give an explanation of what medc and ledc are.