 Complete the following phrase:  Since November 1915, when Serbia was occupied, the Bulgarian army launched crimes against the civilian population. The use of the Serbian language was banned and books in the Serbian language were burned in Niš and Leskovac. Then Bulgarian soldiers started public executions against those that declared themselves Serbian, the worst was in Surdulica, where an estimated 2,0003,000 Serbian men were executed in two years. The Serbs could no longer tolerate the violence of the Bulgarians and in 1917 raised the 