The conference was held to discuss the effect that tourism has the wildlife in the area.A

问题补充：

The conference was held to discuss the effect that tourism has the wildlife in the area.

A. in

B. on

C. at

D. with

答案：

A. in

(答案→)B. on

C. at

D. with

解析：考查固定词组。本题实际上考查的的have an effect on…对…有影响；本题是把the effect提前做完先行词，that指代先行词作为has的宾语。句意：会议被举行来讨论旅游业对这个地区野生动物的影响。故B正确。