Choose the word whose main stressed syllable is placed differently. 1. A. computer B. natural C. certainly D. physicist 2. A. system B. doctor C. chemist D. marine 3. A. present B. address C. away D....

1. The word "certainly" has the main stress on the second syllable, while the other words have the main stress on the first syllable. 2. The word "chemist" has the main stress on the first syllable, while the other words have the main stress on the second syllable. 3. The word "present" has the main stress on the first syllable, while the other words have the main stress on the second syllable. So, for each question, the correct answer is: 1. C. certainly 2. C. chemist 3. A. present