Choose the correct answer.Question 6.I think_______outside in the open air is much more enjoyable than_______exercise in some stuffy gyms.A.walk - to be doingB.walking - doingC.to walk - doneD.having walked – doQuestion 7. They carry on ____ the lessons carefully before the end-of-term exam.A.packingB.doingC.eating     ​​​​​​​D.lendingE.laughing     ​​​​​​​F.reviewing​​​​​​​G.setting ​​​​​​​H.visiting​​​​​​​Question 8.Your blue shirt has been washed, but it still needs_______. Why do you insist_______it today anyway?A.being ironed - to be wearingB.ironing - on wearingC.to have ironed - to wearD.to be ironed - wearingQuestion 9.Trapping too much of the sun’s heat, ________ gases stop it from escaping back into spaceA. consequenceB. greenhouseC. energyD. coalQuestion 10.__________ is a major cause of the loss of forested areas.A. ElectricityB. EmissionC. Fossil fuelD. Deforestation

Sure, here are the correct answers for each question:

Question 6: The correct answer is B. "walking - doing". The sentence should read: "I think walking outside in the open air is much more enjoyable than doing exercise in some stuffy gyms."

Question 7: The correct answer is F. "reviewing". The sentence should read: "They carry on reviewing the lessons carefully before the end-of-term exam."

Question 8: The correct answer is B. "ironing - on wearing". The sentence should read: "Your blue shirt has been washed, but it still needs ironing. Why do you insist on wearing it today anyway?"

Question 9: The correct answer is B. "greenhouse". The sentence should read: "Trapping too much of the sun’s heat, greenhouse gases stop it from escaping back into space."

Question 10: The correct answer is D. "Deforestation". The sentence should read: "Deforestation is a major cause of the loss of forested areas."

The correct answers are:

Question 6: B. walking - doing Question 7: F. reviewing Question 8: B. ironing - on wearing Question 9: B. greenhouse Question 10: D. Deforestation