30. A sky safety system can help cars to__________ traffic jams and crashes. A. prevent B. have C. use D. take 31. People won’t use flying cars__________ the year 2050. A. before B. after C. during D. until 32. Is__________ the most serious problem? A. pollution B. polluted C. pollute D. pollutant 33. We believe that urban transport pods can travel around 30kph. A. with B. at C. in D. on 34. Do you think the__________ price will increase next month? A. fossil fuels B. gases C. fuel D. natural gases 35. We will use more__________ energy in the future. A. solar B. sunny C. sun D. sunlight 36. A jet pack doesn’t__________ a lot of space. A. have B. bring C. take D. occur 37. Which__________ of transport do you think will be used in the future? A. mean B. meaning C. meanings D. means 38. We are looking for types of vehicles that help us to avoid . A. traffic B. traffic jams C. rush hours D. walking 39. The Segway, which is a__________ vehicle, will be a success. A. two-wheels B. two wheels C. two wheel D. two-wheel