As a solidworks 2020 user practicing CSWA associate examples, I have 2 questions.

First,

as I want to extrude all the gear teeth, do I have to select all contour one by one?

Or can I use identical selection method? If I can, I want to know how.

Second,

as using the equation method(global variables) to modify the design of the gear, some of the gear teeth are missed.

How can I figure it out?