1) CH3-CH(CH3)-CH(CH3)-CH2-CH2-CH2) CH3-CH2-CH2-CH2-CH(CH3)-CH2-CH3) CH3-CH(CH3)-CH(CH3)-CH2-CH2-CH2-CH2-CH4) CH3-C(CH3)(CH3)-C(CH3)(CH3)-C(CH3)(CH3)-C(CH3)-CH2-CH2-CH3
1) CH3-CH(CH3)-CH(CH3)-CH2-CH2-CH
2) CH3-CH2-CH2-CH2-CH(CH3)-CH2-CH
3) CH3-CH(CH3)-CH(CH3)-CH2-CH2-CH2-CH2-CH
4) CH3-C(CH3)(CH3)-C(CH3)(CH3)-C(CH3)(CH3)-C(CH3)-CH2-CH2-CH3