[en] The precision temperature dependences of resistivity p(T) for ceramic samples MBa₂Cu₃O_7-x where M is Y, Er, Eu, Gd, Ho, Dy, Er+Y were measured. The samples with high concentration of oxygen (i.e. with low p) showed clear deviation p(T) from linear dependence below 260-270 K. This deviation Δp is positive and its value decreases with decreasing oxygen concentration and arrives Δp=0 for x=0.2. Another factor decreasing value p appearing below 200 K is fluctuation superconductivity. Its contribution was defined for the sample with Δp=0 and accounted in calculation of normal state resistivity p_n(T). Resulted p_n(T) in the range 120-300 K for samples with oxygen concentration close to 7 is typically metallic and agree with classic Bloch - Crueneisen theory. 11 refs.; 2 figs.; 1 tab