7. A, B, C, D, E, F, G ใฎ7ไบบใฎๆฐดๆณณ้ธๆใฎใณใผใน้ ใ, ใใๅผใใงๆฑบใใใจใ, ๆฌกใฎ
็ขบ็ใๆฑใใใ
(1) Aใ1ใณใผในใซใใ็ขบ็
(2) AใพใใฏBใ1ใณใผในใซใใ็ขบ็
(3) Aใ1ใณใผใน, G7ใณใผในใซใใ็ขบ็