What's the biggest obstacle for the railroads heading east from california?

What do you think was a drawback to this method of calculating distance

Hich answer supports the statement, "the state constitution is more detailed than the u.s. constitution"? a) the u.s. constitution was created after state constitutions had been established. b) the u.s. constitution only exists because the state constitutions allowed it to be created. c) the articles in the state constitution do not deal with amendments like the u.s. constitution does. d) the articles in the state constitution deal with more specific issues than does the u.s. constitution.

What important discovery was made by edmond halley and alexis clairaut, using newton's ideas of mathematics and gravity? they created the scientific method to outline how science should be conducted. they were able to find the orbit of a comet and predict the year of its return. they discovered the three newest planets--uranus, neptune, and pluto. they explained why objects appear to have color.