sentence: Maria bought tickets to Lima, Peru as a surprise anniversary gift for Rachel. 
complete: Maria couldn't wait to give her the gift.

sentence: Carrie didn't want to have a baby with their partner, but Mary did. 
complete: Mary never took birth control to prevent pregnancy.

sentence: Monica went to the store, owned by Samantha, to buy a gallon of milk, so 
complete:
Samantha sold the milk.