Analysis 82 Islam 56 Therapeutic use 47 Antioxidants 42 Political activity 42 Carbon, Activated 41 Speech acts (Linguistics) 41 Student activities 40 Surface active agents 40 Medicinal plants 36 Activity programs 34 Study and teaching (Secondary) 34 Purification 33 Study and teaching 32 Sewage 30 Religious aspects 29 English language 28 History 28 Research 27 Absorption and adsorption 26 Academic achievement 24 Case studies 24 Social aspects 23 Students 22 Study and teaching (Higher) 22 Attitudes 21 Environmental aspects 21 Criticism, interpretation, etc 20 Activated sludge process 19 Politics and government 19