The dissociative recombination of HD+ was studied with an adiabatically expanded low-temperature electron beam in the cooler-ring TARN II. Measurements were performed over a wide energy range from 0 to 40 eV in the center-of-mass system, The spectrum at low electron energies of less than 1 eV shows structures even in the energy region on the order of 1 meV. The Experimental results agree well with theoretical calculations based on a multichannel quantum-defect theory including rotational motions. Dissociative recombinations of triatomic molecules, HD2+ and D-3(+), with a non-expanded electron beam are also described.