Please choose the correct ending to complete the given sentence: Travel: [header] How to heat make up water for a boiler system using solar energy [title] Obtain the necessary materials. [step] These are listed below under " things you'll need " but a few of the items will be explained in more detail here. [title] Purchase a solar pathfinder.

Ending1: [step] The solar finder has two settings-1) electric and 2) solar meter. Both are available at most hardware and plumbing stores. Ending2: [title] Assemble the hydrometer, a thermometer, test probes and a 6/8 inch battery powered getameter. [title] Cast the hydrometer to the appropriate heat setting. Ending3: [step] A solar finder is a device that uses heat to improve essential oils. A solar finder looks like a larva-shaped tube, with a paddle attached to the probe. Ending4: [step] A solar pathfinder is needed to measure the estimated amount of sun that will hit the point for the collectors. Directions to how to use this device is located in the instruction manual provided with the device.

Answer format: ending1/ending2/ending3/ending4