201712 Task 4 Directions ： The following is a list of terms related to environment. After reading it, you are required to find the items equivalent to those given in Chinese in the table below. Then you should put the corresponding letters in the brackets on the Answer Sheet , numbered 51 through 55. A. air pollution B. air quality C. alternative energy sources D. carbon emissions E. carbon footprint F. climate change G. electric vehicle H. energy efficiency I. fossil fuels J. greenhouse effect K. zero emissions L. sustainable development M. environmental impact N. solid waste management O. renewable energy