22. The metal roof of a building has turned a light green colour. The metal roof is most likely

The metal roof is most likely made of copper.

Copper turns green over an extended period of time when exposed to water. For example, The Statue of Liberty is made of copper and was once a bronze color. Now, it is green, similar to the roof

Adozen is 12, and your needing to calculate the weight of one medium egg, so i would do 21/12=1.75 per egg, and check your answer by doing 1.75 * 12= 21 : ) : ): ): ): ) i hoped i