3．只有在必要时，我才会开灯。(主谓状结构；when省略句)

　　I shall turn on the lights only when necessary.

　　4．为了节省能源，我将让冰箱和空调以低碳模式(mode)运转。(keep＋宾语＋宾语补足语)

　　I shall keep the refrigerator and air conditioners working in the low­carbon mode to save energy.

　　5．公交车或自行车将是我的首选。(主系表结构)

　　The bus or bicycle will be my first choice.

　　6．当我购物时，我将限制使用塑料袋。(when省略句；主谓宾结构)

　　When shopping, I will limit the use of plastic bags.

　　7．只要有可能，我将把垃圾分成非循环类(non­recyclable)和循环类(recyclable)。(whenever省略句；主谓宾结构)

　　Whenever possible, I will separate my rubbish into non­recyclable and recyclable waste.

　　第四步：句式升级造亮点

　　1．用as引导的原因状语从句连接句1和句2

　　As living a low­carbon life is a good way to reduce the emission of greenhouse gases, I shall carry out my plan in the following ways.

　　2．用并列连词and连接句3和句4

　　I shall turn on the lights only when necessary and keep the refrigerator and air conditioners working in the low­carbon mode to save energy.

　　3．用not only ... but also ...且not only位于句首合并句6和句7

　　Not only will I limit the use of plastic bags when shopping, but also I will separate my rubbish into non­recyclable and recyclable waste whenever possible.

　　第五步：过渡衔接联成篇

　　Dear John，

　　You have asked for my advice on how to live a low­carbon life and I will try to make some suggestions.With the environmental pollution going from bad to worse, I sincerely suggest to all that we should live a low­carbon life today.

As living a low­carbon life is a good way to reduce the emission of greenhouse gases, I shall carry out my plan in the following ways. To begin with, I shall turn on the lights when necessary and keep the refrigerator and air conditioners working in the low­carbon mode to save energy. Additionally, the bus or bicycle will be my first choice. Last but not least, not only will I limit the use of plastic bags when shopping, but also I will separate my rubbish into non­recyclable and recyclable waste whenever possible.