1 What is the difference between regular and supreme? Why is the price of the supreme more than regular? 1` If we use the Regular brand, is there will be effect on the engine?2 How can we stop or minimize the flow of metallic lead to the environment?3- explain the causes of the following issues: green house effect, global warming, Photochemical smog, acid rain and climatic changes. 4 Scale formation is a major issue in the steam boiler. How could this issue been resolved?5 Draw a labelled homemade water treatment plant6 which are other alternative energy sources (other than petroleum) in Oman which can be used to produce electricity and run cars? 7 what is the meaning of the terms conservation and recycling? How can we use them in Oman?8- Sohar industrial area has been grown as one of the major industrial sectors of Oman. What will be the immediate effects on the local residents in terms of socio-economic conditions?