Ответ:

CH3

|

1)CH3–C–CH2–CH2–CH3

|

OH CH3

2). |

CH3–CH–C–CH–C–CH3

| | | |

OH CH3 CH3 CH3

CH3

|

3)CH3–CH—C–CH–CH2–CH2–CH3

|. | |

OH. CH3 C2H5