Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to calculate the volume of an irregular object [title] Make sure the object is waterproof before you begin. [step] This method involves submerging the object in water. If the object is hollow and not watertight, you cannot get an accurate measure of volume using this method.

Ending1: If the object absorbs water, make sure water will not damage it, and read the instructions carefully to see how to adjust the process. Never drop an electric or electronic item in water, as this could cause a dangerous electrical shock and/or damage the object beyond repair. Ending2: But it is quick, easy, and usually well-hydrated, so you will get an accurate result in terms of volume. [substeps] For example, if the object is sealed with vegetation surrounding it, you can still get an accurate measure. Ending3: And, what you do know for sure is that pouring water onto the object will always lead to an inaccurate result that your best bet is simply to give it a five-millimeter test. [title] Use a camera to measure the volume. Ending4: [substeps] If the object is clear or colorless, this method may only work at that depth. [title] Soak the object in the water for an hour.

Answer format: ending1/ending2/ending3/ending4