@sunnysansandhu: 1. must be + _____ → usually third form (past participle) The application must be submitted. The equipment must be checked. Look for V3: completed, provided, installed, collected, etc. 2. a / an + _____ → usually a singular countable noun an employee a vehicle an application If there is an adjective too: a large building. 3. many / several / various / numerous + _____ → plural noun many students several problems So expect an -s/-es plural in many cases. 4. one / each / every + _____ → singular noun each student every employee one ticket 5. two / three / a number of + _____ → plural noun three documents a number of activities 6. _____ or colours → the blank will very likely be parallel with “colours.” If the second item is a plural noun, predict another plural noun: different sizes or colours various shapes or colours