So ich fang dann mal mit Englisch an!(Ist zwar ne sache die man persönlich machen muss, versuche es aber trotzdem!):

• 2b:1.-,2.Both traffic jams and accidents are caused by cars! oder:Either traffic jams  or accidents are caused by cars!3.Either cycling or walking is very healthy!oder:Both c. and w. is very healthy! 4.Either waste energy or damage the environment is caused by less responsibility!(verantwortung) oder:Both waste energy and damage the environment is caused by less responsibility(verantwortung)5.Cars are both expensive and dangerous!oder:Cars are either expansive or dangerous!
• 3 müsst ihr schon selber aussprechen!;-)