选词填空
　　36. B. caters
　　37. M. recommended
　　38. D. debated
　　39. F. ideal
　　40. C. chronically
　　41. G. improvements
　　42. E. deprivation
　　43. L. ready
　　44. H. necessarily
　　45. O. target
　　仔细阅读：
　　61. It has aroused public attention to safety issues.
　　62. It has sent half a dozen passengers into space.
　　63. To promote the space tourism industry.
　　64. Suspend Virgin Galactic’s Lisence to take passengers into space.
　　65. It is worth promoting despite the risks involved.
　　长篇阅读：
　　C 46. Not only moving objects and people but all systems have momentum.
　　I 47. Changing the current energy system requires the systematic training of professionals and skilled labor.
　　E48. Changing a light bulb is easier than changing the fixture housing it.
　　K49. Efforts to accelerate the current energy transitions didn’t succeed as expected.
　　G 50. To change the light source is costly because you have to change the whole fixture.
　　A 51. Energy systems, like an aircraft carrier set in motion, have huge momentum.
　　G 52. The problem with lighting, if it arises, often doesn’t lie in light sources but in their applications.
　　J 53. The biggest obstacle to energy transition is that the present energy system is too expensive to replace.
　　D 54. The application of a technology can impact areas beyond itself.
　　B 55. Physical characteristics of moving objects help explain the dynamics of energy systems.