You may have noticed that the place of birth of your ancestors changed between the 1910 and 1920 US censuses. Your Austrian great great grandparents are suddenly Czech. Your ancestors were not confused, instead the map of the world changed as a result of World War I. Many of the countries that we now take for granted were part of great multi-ethnic empires. Two great empires were dismembered as a result of the war, the Austro-Hungarian Empire and the Ottoman Empire.
Before 1918 much of the Arabic-speaking world was ruled by the Ottoman Empire, often referred to simply as "Turkey". As a result, in early records your Syrian or Lebanese ancestors may be listed as being "Turks" or as being from "Turkey".
One such immigrant was Joseph Robbie, the father of Joe Robbie, the founder and original owner of the Miami Dolphins. In 1914 he married Jennie Reedy in Sisseton, South Dakota. In this record, which can be found in the South Dakota Marriages, 1905-1949 collection on Ancestry.com, he is listed as a "Turk".
Just 6 years later he is listed as being from "Syria" in the 1920 Census.
Remember that just because your ancestor is listed as a "Turk" or as being born in "Turkey" does not mean that your ancestor were ethically Turks or spoke Turkish. Many of the immigrants from before WWI were Arabic-speaking Christians from what is now Lebanon and Syria.