Business English 10th Edition by Mary Ellen Guffey,Carolyn Seefer

تمرين 63

Insert necessary commas. In the space provided, indicate briefly the reason for the comma or its absence (for example, independent adjectives, introductory verbal phrase, introductory clause , and so forth). Write C if the sentence is correct.
The "picturephone" was demonstrated at the 1964 World's Fair but the device never became popular with consumers. ________________