16-20.BDDBC 21-25.DDBA D

　　26-30 CABDB 31-35 BDACB 36-40 BACAC

　　41-45 ADBBA 46—50 CDACB 51—55 DABDC 56-60 DAECB

　　61 wasn’t 62 agreed 63 up 64 others 65 through

　　66 outstanding 67 excitedly 68 happened 69 finally 70 love

　　71.amazing 72.between 73.smiling 74.realized 75.decisious

　　76.regretted 77.caused 78.present 79.helpful 80.including

　　參考范文：

　　Dear Jack,

　　Thank you for your letter asking about our discussion on low carbon lifestyle. Here is something about it.

　　We can do a lot in our daily life to achieve the goal of living low carbon life. First, we’d better turn off lights if possible and spend less time watching TV or surfing the Internet. Saving water also matters much. Besides, we should sort out the rubbish, hoping that we might recycle some, which will surely benefit us a great deal. In addition, we suggest using handkerchiefs instead of tissues so that we can prevent more trees from being cut down. More importantly, when we go out, walking, riding bikes or taking buses should be our first choice, which contributes to a cleaner world.