Problem: Continue the following story.

Billy was preparing the mixture in the kitchen and added vinegar but not oil because the 
OPTIONS:
- vinegar was scarce.
- oil was scarce.
Here's how I want to continue it: oil was scarce.

Problem: Continue the following story.

Mary's dress was wrinkle free and had perfect pleats but not Erin's because 
OPTIONS:
- Mary owned an iron.
- Erin owned an iron.
Here's how I want to continue it: Mary owned an iron.

Problem: Continue the following story.

Elena whispered to Christine that she was a fugitive from the law.  
OPTIONS:
- Elena was shocked.
- Christine was shocked.
Here's how I want to continue it:
Christine was shocked.