What has thirteen hearts, but no other organs?

I can be found in a science lab or in the Muppets

Something tall basketball players get lots of. When one relationship ends and another begins. A book that has been repaired.

What kind of key can't fit in a lock but can turn a handle without any doubt

A cannonball causes a large one A jack knife a little less so A rip entry, hardly none But a belly flop? Look out below!