Some feel smooth because it has been eroded away by the current of the water for a very, very long time. The more rough rocks have not been succumb to as much erosion, therefore it is not smooth yet.
The rock that is very smooth is most likely the one that was found in riverbed because the river would probably toss the rock around and weather it down until it is smooth. Therefore, that means that the other rock was most likely found underground.
River stones, river rock, or skipping stones
Mississippi River is to US as Nile River is to Egypt. This analogy is comparing the river to the country it is located in. The Mississippi River is located in the United States and the Nile River is located in Egypt.
The Niger River is found in the continent Africa.
what is 1+1=2
It depends on how big is the dolphin and who are you comparing to and which dolphin.
The river in Nubia is different from the one in Egypt because the Nile River in Nubia is not to smooth as the Nile River in Egypt.
Where ever a river is found
No they are not. River rock is rounded and smooth where crushed rock is sharp and jagged.
Louis Joliet and Father Jacques Marquette (and five others) found the Mississippi River in 1673.
Newfoundland, around 1535. Of course others had been there before him so it wasn't a big discovery. He did take it farther than others and found a river.
Rail is much faster than river travel.