A (student progress) can be sustained.Logical formLearned from3 sentences. Epidemics can be sustained.Logical formLearned from3 sentences. Gales can be sustained.Logical formLearned from3 sentences. A (food production) can be sustained.Logical formLearned from3 sentences. An (espionage effort) can be sustained.Logical formLearned from3 sentences. A revolution can be sustained.Logical formLearned from3 sentences. A block can be sustained.Logical formLearned from3 sentences. A betterment can be sustained.Logical formLearned from3 sentences. An occupancy can be sustained.Logical formLearned from3 sentences. A respite can be sustained.Logical formLearned from3 sentences. A (growth spurt) can be sustained.Logical formLearned from3 sentences. A panic can be sustained.Logical formLearned from3 sentences. An engine can be sustained.Logical formLearned from3 sentences. A strain can be sustained.Logical formLearned from3 sentences. An ethnic cleansing can be sustained.Logical formLearned from3 sentences.