题目

 Studying Wendy’s menu, I found that many of the items are similar to _____ of McDonald’s. A. those                       B. ones                       C. any                 D. all 答案：B以下生态系统中，最稳定的是（ ）A．森林生态系统B．农田生态系统C．草原生态系统D．沙漠生态系统