Please answer the following questions based on the case study as described above. 1. Describe the main and subsidiary research. (20 marks) 2. Describe the unit of analysis used in the first paper (Gong et al). (5 marks) 3. The above studies used sampling method. In your opinion, is this sampling method appropriate or should it be a census study? Give FOUR (4) reasons to support your answer. (20 marks) 4. The research papers in the case study above have mainly applied random sampling method. If you were to carry out the same research, what would be your choice of sampling method? Explain your choice. (15 marks) 5. From five research studies cited in the case above, explain TWO (2) significant conclusion related to smoking. (20 marks) 6. If a smoking research study is to be carried out in Malaysia, how would you expand the scope of the study? (20 marks).