Benjamin drank Dennis's juice when they weren't looking last night so 
OPTIONS:
- Benjamin was looking for the bottle.
- Dennis was looking for the bottle.
Dennis was looking for the bottle.

Joel's friends were all busy while Derrick's friends were available, so 
OPTIONS:
- Joel went to the concert with others.
- Derrick went to the concert with others.
Derrick went to the concert with others.

Michael spent the day writing a personal letter to Nick, so 
OPTIONS:
- Michael was happy to hear they read it.
- Nick was happy to hear they read it.
Michael was happy to hear they read it.