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.

　　E 48. Changing a light bulb is easier than changing the fixture housing it.

　　K 49. 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.

　　考后關(guān)注：2015年12月英語六級(jí)成績查詢　合格分?jǐn)?shù)線　算分器