I want to make a checkbox widget mandatory, so if the user doesn't select all the checkboxes a popup will show saying "no" and if they do check all the checkboxes something else will popup saying "yes" How do I do this with the Tkinter module in python?

What does a cascading style sheet resolve a conflict over rules for an element? a. the rule affecting the most content wins b. the rule affecting the most content loses c. the rule with the most specific selector loses d. the rule with the most specific selector wins

Least square fit to polynomial write a function leastsquarefit3pol that solves a linear system of equations to find a least squares fit of a third order polynomial to an experimental data set given as two row arrays. the function leastsquarefit3pol must explicitly solve a set of linear equations and cannot use polyfit. there should be no restriction on the size of the problem that can be solved.

Martha is designing a single-player game. her manager suggests that she plan the design to incorporate future modifications. which principle of game design relates to planning for future modifications?