We had planned to climb the hill this morning but the heavy rain our plan.A. settled B.

问题补充：

We had planned to climb the hill this morning, but the heavy rain our plan.

A. settled

B. ignored

C. upset

D. received

答案：

A. settled

B. ignored

(答案→)C. upset

D. received

解析：考查动词：A. settled定居，解决，B. ignored忽视，C. upset使不安，使难过，扰乱，D. received收到，句意：我们本来计划今天早上爬山，但是大雨扰乱了我们的计划。选C。