C2H6 、H H-C-C H H H Do the same to the other side: Sp3 Sp3 Sp3 Sp3 Bring the two halves together: Success! X-7C2H6 Do the same to the other side: Bring the two halves together: C C H H H H H H sp3 sp3 sp3 sp3 H H H C H C H H XI-7