The best and most correct answer among the choices provided by the question is the second choice. The cause of studying rocket technology was that to explore the "last frontier". I hope my answer has come to your help. God bless and have a nice day ahead!
The Progressive party managed to attract Democratic voters in the southern states <span>of the following was the key reason for Coolidge’s victory in the 1924 presidential election, but it wasn't key reason Coolidge was very popular due to his economic policies</span>
It became more assertive by the U.S. expanding its borders into Florida and through their foreign affairs that included the Monroe doctrine preventing Europe to interfere with Latin American political affairs.
A constitutional democracy
1. Julius Caesar conquered Gaul
