UNDERSTAND, RECALL, APPLY & EVALUATE THE CONCEPTS YOU HAVE LEARNT IN SCIENCE TO ANSWER THE FOLLOWING QUESTIONS: Q3. Yusuf & Ahmed were investigating ‘rusting’. They set up 3 test tubes for their investigation as follows: Test tube 1 had water & uncoated iron nails. Test tube 2 had water & greased iron pins. Test tube 3 had water & galvanized iron screws. 3a) PREDICT in which test tube they will find ‘rusting’ taking place. * EXPLAIN the results/observations in EACH test tube.