text: SELECT name FROM world
  WHERE population >
  (SELECT population FROM world
  WHERE name='Russia')
  
  SELECT name
  From world
  WHERE continent = 'Europe' AND gdp/population > (SELECT gdp/population FROM world WHERE name
  ='United Kingdom')
  
  SELECT name, continent
  FROM world
  WHERE continent = (SELECT Continent FROM world  WHERE name = 'Argentina') OR continent = (SELECT
  Continent FROM world WHERE name = 'Australia') ORDER By name
  
  SELECT name, population
  FROM world
  WHERE population > (SELECT population
  FROM world
  WHERE name ='Canada')  AND population < (SELECT population FROM world WHERE name ='Poland')
  
  SELECT name, ROUND((population/(SELECT population FROM world WHERE name ='Germany'))*100) || '%'
  FROM world
  WHERE continent = 'Europe'
  
  SELECT name
  FROM world
  WHERE gdp > ALL(SELECT gdp
  FROM world
  WHERE name ='Germany')
  
  SELECT continent, name, area FROM world x
  WHERE area >= ALL
  (SELECT area FROM world y
  WHERE y.continent=x.continent
  AND area>0)
  
  SELECT continent, MIN(name) AS name
  FROM world 
  GROUP BY continent
  ORDER by continent
  
  SELECT name, continent, population FROM world x
  WHERE 25000000>=ALL (SELECT population FROM world y
  WHERE x.continent=y.continent
  AND population>0)
  
  SELECT x.name, x.continent
  FROM world x
  WHERE x.population >ALL(SELECT population*3
  FROM world y
  WHERE y.continent = x.continent
  AND x.name<>y.name)
  
  