CREATE TABLE table_23923 ("Country/Region" TEXT, "Title" TEXT, "Television network" TEXT, "Winners" TEXT, "Presenters" TEXT, "Trainers" TEXT)

Silvio Santos is the presenter in what country?
SELECT "Country/Region" FROM table_23923 WHERE "Presenters" = 'Silvio Santos'
SELECT "Country/Region" FROM "table_23923" WHERE "Presenters" = 'Silvio Santos'