I, Choose the word whose main stress is placed differently from the others.
| 1) | a.necessary | b.behavior | c.excellent | d.grammar |
| 2) | a.report | b.improve | c.spanish | d.revision |
| 3) | a.semester | b.celebrate | c.signature | d.semester |
| 4) | a.participation | b.festival | c.fairy | d.present |