Hmm....
This is straight from my own Memory but which Catherine the Great was it?
If it is the second one, then I would Say either C or D
(Sorry Im too lazy to search up :v)
No because what happens when you run out of workers?
Answer:
the book will not move its own but it is removed by applying other external force
The Kansas River stop was most likely the most dangerous stop of the Oregon Trail.
Rivers crossing was usually dangerous for settlers with unpredictable tides ran the risk of drowning, losing livestock, losing important supplies, or overturning wagons.