`CH_(3)-CH_(2)-UNDERSET(O)underset(||)(C)-H` and `CH_(3)-underset(O)underset(||)(C)-H` `H-underset(O)underset(||)(C)-H` and `CH_(3)-CH_(2)-underset(O)underset(||)(C)-CH_(3)` `CH_(3)-underset(O)underset(||)(C)-CH_(3)` and `H-underset(O)underset(||)(C)-H`