For any relation R, if, for every valid instance of A, that value of A uniquely determines the value of B: A. then a primary dependency exists in the relation. B. then A is said to be functionally dependent on B. C. then B is said to be functionally dependent on A. D. then A and B are candidate keys for the relation. E. None of these are true.

Description: write function lastfirst() that takes one argument—a list of strings of the format "lastname, firstname" —and returns a list consisting of two lists: (a) a list of all the last names (b) a list of all the first names

Jason is working on a microsoft excel worksheet and he wants to create a print preview shortcut. his teacher asks him to access the customization option to create the new shortcut. which two tabs should jason select to place the print preview shortcut on the worksheet toolbar? a. new tab (custom) and new group (custom) b. new file tab (custom) and new tab (custom) c. new custom group and new command d. new custom tab and new command

Which two technologies support the building of single-page applications?