What do these episodes have in common?

Beaver The Magician
Train Trip
Beaver's Prep School

Hint: Notice I didn't include Beaver's Short Pants.

Beaver went away on a trip in all three of those episodes.

Those were episodes with Aunt Martha.

That's not the answer yet. Beaver didn't take a trip in Prep School. They did all have Aunt Martha but I didn't include Beaver's Short Pants with Martha.

Guess again. Martha is part of the answer.

Ans. In all those episodes Martha is on the phone (actually see her) to either Ward or June. In Visiting Aunts she does call June but they don't show her.

What do these episodes have in common?

Lost Watch
Beaver's Library Book
Beaver's Tree
Beaver's Baby Picture
Beaver The Model to name a few

It's been so long since I posted this question but I think the answer was that in all these episodes Beaver had a hypothetical question for Ward or June and wound up acting on the advice. Like in Lost Watch he asks Ward if you gave a bank your money to mind and they lost it would you call the police? Ward says he would. In Library Book he thinks they'll put his father in jail and June says she'd be upset if he didn't come home. The others have similar situations of Beaver asking questions.