Here are the best responses for each question based on the information provided:
Question 19:
The judicial branch has the ability to declare a law unconstitutional.
Question 20:
Trade became complicated because states printed their own currencies.
Question 21:
He refused to sign the United States Constitution.
Question 22:
by allowing the people to choose their representatives.
Question 23:
- A system of checks and balances is designed to prevent abuse of power.
- The separation of powers ensures that no one branch has too much power.
(Note: For Question 23, since it asks for all that apply, the last two options provided are the most accurate.)