题目

地球上最大的生态系统是（ ） A . 荒漠生态系统 B . 草原生态系统 C . 生物圈 D . 海洋生态系统 答案：C— _________________________________— I'd like some tomatoes and mutton. [     ]A. What do you have for lunch?B. What do you like?C. What would you like for lunch?