When creating a template file, Word saves the file with which extension?

The following is an example of a ________ citation in MLA style. Jackson, G.S. "The Advantages of Social Network Sites." Chron. Houston Chronicle, 5 July 2012. Web. 8 November 2015

A) web page B) book C) magazine article D) journal

Excel's ________ identify the worksheets in a workbook

Fill in the blank(s) with correct word