How to extend all iMovie clips?

[Gary King]

How can I extend all iMovie clips? I only know how to extend one at a time. I tried Select All then changed the time length, but apparently, that only affects one clip?

 

[Artful Dodger]

When you say clip do you mean the transition or the video/photo itself?
I just want to make sure I'm thinking of the same thing before I blurt out a few things