. by the advances in technology many farmers have set up wind farms on their land. A. Bei

问题补充：

. by the advances in technology, many farmers have set up wind farms on their land.

A. Being encouraged

B. Encouraging

C. Encouraged

D. Having encouraged

答案：

A. Being encouraged

B. Encouraging

(答案→)C. Encouraged

D. Having encouraged

解析：根据句意和空格后的介词by短语可知，空格处应填一个表被动意义的选项，故可排除B和D；而选项A为现在分词的被动式，除表示被动外还表示动作在进行，与句意不符，故也排除。