What is a " primordial substance" and how does that term relate to Empedocles ?

Carefully retyoe the sentence , when we are in washington, d.c, we like to visit the smithsonian institution and the washington monument

What was the major sacrifice the members of the continental congress dealt with? how did they overcome this obstacle?

What are the adjectives in this sentence? our ancient car has became very unreliable recently,so we are trying to find a cheap replacement .