Grammar

Look at the sentences below. Choose the correct construction of the infinitive of purpose. HELP
1)He was proficient enough… as a telegrapher full time.

2)An electric vote recorder is a device intended for use by elected bodies such as Congress … the voting process.

3)As a child, Charles Babbage was sent to a country school … from a life-threatening fever.

4)Thomas Edison was invited to the White House … the tin foil phonograph.

5)The results were so breathtakingly original, that it took some time for the mathematical and engineering community … their significance.

6)In 1970, NASA leadership asked von Braun to move to Washington, D.C., … the strategic planning effort for the agency.

7)Nikola Tesla built an experimental station in Colorado Springs … with high frequency electricity and other phenomena.