PLEASE HURRY TY How did Andrew Carnegie make his fortune?

He established electricity companies all over the world.

He established a network of radio companies.

He produced steel very efficiently.

He set up telegraph offices in the United States
and Europe.

Which indo european tribe developed a strong warrior society and built an empire that was frequently invaded by those seeking fertile land

Iwill be giving 15 points to whoever answers the concept of checks and balances means that each branch of governmenta. has its own powers and responsibilitiesb. is clearly described in articles of the constitutionc. has the ability to correct the other branches in case of an errord. is set up so that in case of constitutional crisis, the governement will continue to operate

Which one of the following statements best characterizes change to agriculture in the united states since 1900