Abstract: A multi-gas-source heater is disclosed including a main shell, an ignition apparatus, a pipeline system arranged on the main shell, a temperature-sensing valve, a burner and a switching valve; the pipeline system has a first and second communication states; the temperature-sensing valve is connected to the pipeline system and can regulate flow of output gas; the burner includes a first and second nozzles both connected to the pipeline system; the ignition apparatus is connected to and can ignite the burner; the switching valve is connected to and can switch the pipeline system between the first and second communication states; when the switching valve switches the pipeline system to the first communication state, the first nozzle outputs the gas; when the switching valve switches the pipeline system to the second communication state, the second nozzle outputs the gas, or the first and second nozzles both output the gas.

Abstract: A cutter and a cutting method for concrete test blocks, where an upright column is fixed at left-rear end of a base, a support for an electric motor provided at rear end thereof is provided on an upper part of the column, a driving gear is provided at left side of the electric motor, a driven gear is connected with the driving gear via a belt, a control switch is provided at a front end of the support, a grip is provided at right side of the control switch, a transmission shaft is connected to right side of the driven gear, double sawblades are provided at right end of the transmission shaft, a shield is provided above the double sawblades, a water pipe is connected to an upper part of the shield, the clamp is provided at right-front end of the base and the handle is connected to the grip.