=SUM(A6:19,sheet3!A12)
which part of the formula references the work sheet?

In which phase does software coding and testing happen in the spiral model? the spiral model does not have a separate testing phase. both, software coding and testing occurs during the phase.

The more powerful, 60 volt cables and the main power shut off on an hev are both colored orange

The best definition of an idiom is a. a word or phrase that describes a noun b. a word or phrase describing a verb c. a phrase containing figurative language in which the word expresses a different idea from its exact meaning d. a phrase that compares two unlike objects or ideas