单选题 Talks on climate change resumed in the German city of Bonn on July 16 to combat global warming.
A. focus on B. settle down C. fight against D. sum up

【正确答案】 C
【答案解析】combat意为“与……战斗，与……斗争”，focus on意为“集中”，settle down意为“定居，安顿下来”，fight against意为“与……做斗争”sum up意为“总结”。故答案为C。