Switzerland is the only landlocked country in the question's list.
no
No, its a land locked country
Sudan
Yes.
False. Greece is not a land-locked country, as it is surrounded by water on three sides: the Ionian Sea to the west, the Aegean Sea to the east, and the Mediterranean Sea to the south.
Laos
Moldova
No, Switzerland is a land-locked country.
Of course it can.
No, it is an island!
Chad, Mongolia just to cite landlocked countries. Israel, Tunisia if the definition of "ocean" is stricto sensu (they are bordered by the Mediterranean Sea, not an ocean). Only some island countries (Australia, etc..) are "surrounded" completely by water.
No. Bolivia is a land locked country.