1179 United States v. 1,014.16 Acres of Land in Vernon Cty., 558 F. Supp. 1238, 1242 (W.D. Mo. 1983), aff’d, 739 F.2d 1371, 1373 (8th Cir. 1984) (“The district court properly noted that in condemnation cases, federal procedural and evidentiary rules apply.”); seeFed. r. eVid. 703 (bases of an expert opinion).