Exercises can be compulsory.Logical formLearned from115 sentences. Units can be compulsory.Logical formLearned from113 sentences. Military service can be compulsory.Logical formLearned from112 sentences. An (education law) can be compulsory.Logical formLearned from111 sentences. (Identity cards) can be compulsory.Logical formLearned from107 sentences. A language can be compulsory.Logical formLearned from105 sentences. A (school age) can be compulsory.Logical formLearned from105 sentences. Primary education can be compulsory.Logical formLearned from103 sentences. An education can be compulsory.Logical formLearned from103 sentences. A system can be compulsory.Logical formLearned from100 sentences. A program can be compulsory.Logical formLearned from93 sentences. An element can be compulsory.Logical formLearned from92 sentences. A use can be compulsory.Logical formLearned from91 sentences. An (education program) can be compulsory.Logical formLearned from88 sentences. A membership can be compulsory.Logical formLearned from86 sentences.