What group of people in the russian empire were forbidden to own land?

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

On the map below, which of the following rivers is identified by blue? the huang he river the yangtze river the han river the naktong river

The european union was formally established in