Practice Rules 4-8: Add the needed commas to the following sentences. a. Existing structures include a 40-foot diameter morning glory intake a 10-foot rectangular spillway a fish ladder and a 30 inch conveyance pipe that passes through the dam b. [Opening of an e-mail] Hi Sophia Michael just sent me a question about the models. (e-mail continues) c Groundwater observation wells are generally used if precise groundwater table information is needed. However the installation of wells was not deemed critical for the design of this project. d. On January 8 2015 our team met with the president and founder of the Blue Organization. e. Our explorations indicate that native soils in the project area consist of a relatively thin layer of loose dry silty sand overlying weathered basalt rock. [Note: "silty sand" is a term for classifying soil types. It is a single term.]