(1) Experimental idea: Determining whether three pairs of genes are located on three pairs of chromosomes is divided into determining whether every two pairs of genes are located on one pair of chromosomes. For example, use ① and ② to perform hybridization to determine Are A/a and B/b located on a pair of chromosomes? Experimental process: (Take determining whether A/a and B/b are located on a pair of chromosomes as an example) Expected results and conclusions: If the phenotype and proportion of F 2 are normal setae with eyes: small setae with eyes: normal without eyes Setae: small eyeless setae = 9:3:3:1, then A/a and B/b are located on two pairs of chromosomes; otherwise A/a and B/b are located on the same pair of chromosomes. (2) Experimental idea: Verify that both pairs of genes A/a and B/b are located on the X chromosome, and split them into verifying that A/a is located on the X chromosome and B/b is located on the X chromosome. For example, use ① and ③ to conduct hybridization experiments to verify that A/a is located on the X chromosome, and use ② and ③ to conduct hybridization experiments to verify that B/b is located on the X chromosome. Experimental process: (Take verification that A/a is located on the /a is located on the X chromosome; if all offspring have eyes and the number of males and females is equal, then A/a is located on the autosome. Therefore, the answer is: (1) Select three hybrid combinations ①×②, ②×③, and ①×③ to obtain F 1 and F 2 respectively. If four phenotypes appear in F 2 of each hybrid combination, and the proportion is 9:3:3:1, it can be determined that these three pairs of alleles are located on three pairs of chromosomes respectively; if other results occur, it can be determined that these three pairs of alleles are not located on three pairs of chromosomes respectively (2) Select ① ×②Hybrid combinations are used for reciprocal crosses and the phenotypes of F 1 male individuals are observed. If the male individual in F 1 obtained by orthogonal cross and the male individual in F 1 obtained by reciprocal cross have different expressions of the two pairs of relative traits of eyes/no eyes and normal setae/small setae, it proves that both pairs of alleles are Located on the X chromosome