My calculations were based on the that house prices would remain steady.
A. theory
B. regulation
C. procedure
D. assumption
网友回答
A. theory
B. regulation
C. procedure
(答案→)D. assumption
解析：句意，我的计算是以假定房价稳定为基础的。Theory理论regulation 规则procedure程序assumption假定，根据题意，故选D。