With gupta advancements in mathmatics and astronomy, which of the following discoveries were most important to future generations? mark all that apply.

1) use of zero as a placeholder

2) numeric decimal system

3) observing the earth to be round due to shadows

4) concluding the earth spins on an axis

5) use of coins as money

in the 1800s, locomotives powered by steam made transportation faster and cheaper. the resulting rapid growth of railroads led to the connection of the atlantic and pacific railroad in oklahoma city in 1897.

in the last years of the century, the improvement of steam-based engines the expansion and growth of railroads. this growth increased when the companies started to build and expand, such as the atlantic and pacific railroad, which connected new mexico with california, and missouri with oklahoma. many of these new networks were built in oklahoma, and these changes transportation henceforward.