________ is a kind of lipid used as a waterproofing material in plants.

Sure, here are step by step solutions for a problem related to waxes: **Problem:** How can we separate a mixture of wax and oil? **Solution:** 1. First, heat the mixture of wax and oil to a temperature where the wax melts and the oil remains liquid. 2. Allow the mixture to cool down slowly. As it cools, the wax will solidify and separate from the oil. 3. Once the mixture has cooled down completely, skim off the solidified wax from the top of the liquid oil. 4. If there is still some wax mixed in with the oil, filter the liquid through a filter paper or cloth to remove any remaining solid particles. 5. The filtered oil can be further purified by distillation to remove any impurities. $\boxed{\text{Mixture of wax and oil}\stackrel{\text{Heat}}{\to }\text{Melted mixture of wax and oil}}$$\boxed{\text{Melted mixture of wax and oil}\stackrel{\text{Cooling}}{\to }\text{Solidified wax and liquid oil}}$$\boxed{\text{Solidified wax}\stackrel{\text{Skimming}}{\to }\text{Separated wax}}$$\boxed{\text{Separated oil}\stackrel{\text{Filtration}}{\to }\text{Filtered oil}}$$\boxed{\text{Filtered oil}\stackrel{\text{Distillation}}{\to }\text{Purified oil}}$