Scientists use potassium-argon method to determine the age of a rock sample. three separate tests showed the rock to be 1.3 billion years old. however, scientists know the rock must be at least 2.5 billion years old based on the rocks around it. how is this possible?

a and b!

dfroos means which is a and b

basic principles: federalism, separation of powers, checks and balances, judicial review, representative democracy, limited government, rule of law, individual rights and responsibilities, consent of the governed, majority rule, popular sovereignty, equal protection.

ww1 weapons: tank. tanks were used for the first time in the first world war at the battle of the somme. they were developed to cope with the conditions on the western front. the first tank was called 'little willie' and needed a crew of 3.