Article with geographical names

Will we use the definite article “the” or zero article before rivers?

Will we use the definite article “the” or zero article before group of mountains?

Will we use the definite article “the” or zero article before a mountaintop?

Will we use the definite article “the” or zero article before deserts?

Will we use the definite article “the” or zero article before continents?

Will we use the definite article “the” or zero article before towns?

Will we use the definite article “the” or zero article before countries whose name includes a word like REPUBLIC OR UNITED?

Will we use the definite article “the” or zero article before group of lakes?

Will we use the definite article “the” or zero article before oceans?

Will we use the definite article “the” or zero article before groups of islands?

... Danube is the longest river in .. Europe.

... UK is situated on ... British isles.

A Dutch lives in ... Netherlands.

...Germany, ... Italy, ...Turkey and other countries are the members of ... European Union.

We went to _______Adriatic Sea last summer.

Ussuri bear lives in_______Himalaya Mountains.

The capital of _______Republic of Ireland is _______Dublin.

Ireland is situated in ______ north-west of _____Europe.

It is washed by the waters of _______Atlantic Ocean.

______Alps are in Switzerland.

Washington is___capital of___USA.

Lee was born in _______ China but she lives in ______ United Kingdom of Great Britain and Northern Ireland.

I went sailing around_______ Lake Geneva.

________Mount Everest is the highest mountain in the world

_______Pacific Ocean has many different types of fish

He has always wanted to visit _______ Rome.

I spent a year travelling around_________ Europe.

They live near  ______Thames.

They studied the geology of ______ Sahara Desert.

Her husband comes from________ California.