Electron cloud modle should be the answer
1. sewage system - facility consisting of a system of sewers for carrying off liquid and solid sewage. sewage works, sewer system. facility, installation - a building or place that provides a particular service or is used for a particular industry; "the assembly plant is an enormous facility"
Answer: Here you go!
Explanation:
Analogous structures are structures that are similar in unrelated organisms. The structures are similar because they evolved to do the same job, not because they were inherited from a common ancestor. For example, the wings of bats and birds, shown in Figure below, look similar on the outside