To meet scientists' recommendations, total global CO2 emissions should be reduced to about
million metric tons.
16,000
34,000
22,000
The last time that global CO2 emissions were at or below this level was in the
1990s
1970s
2000s

The telegraph, the transatlantic telegraph cable, and the telephone were important to businesses after 1850 because of a. they created a system for developing new inventions. b. they filled a need that other inventions of the day could not. c. they attracted investors and created the stock market. d. they made picture-taking a popular american pastime.