1) Our country has an extremely varied climate.
Our country had an extremely varied climate.

2) Russia is washed by three oceans: the Atlantic, the Arctic and the Pacific.
Russia was washed by three oceans: the Atlantic, the Arctic and the Pacific.

3) The seas of the European part of Russia are linked by vast canals.
The seas of the European part of Russia were linked by vast canals.

4) The southern regions of Russia are situated in subtropics.
The southern regions of Russia were situated in subtropics.

5) Climate differs greatly from place to place.
Climate differed greatly from place to place.

6) Many rivers flow through the territory of Russia.
Many rivers flowed through the territory of Russia.

7) Climate is varied because of its vast territory.
Climate was varied because of its vast territory.

8) Russia lies within the arctic, subarctic and temperate zones.
Russia lay within the arctic, subarctic and temperate zones.