Problem: Continue the following story.

Betty asked for a scholarship recommendation from Sarah , as 
OPTIONS:
- Betty offered her knowledge and expertise as a teacher.
- Sarah offered her knowledge and expertise as a teacher.
Here's how I want to continue it: Sarah offered her knowledge and expertise as a teacher.

Problem: Continue the following story.

the box became weaker after it was soaked in water but the bowl is still strong because the 
OPTIONS:
- box is waterproof.
- bowl is waterproof.
Here's how I want to continue it: bowl is waterproof.

Problem: Continue the following story.

The chemistry class had to chose between two abrasive chemicals in the experiment. They ended up choosing the acid over the base because the 
OPTIONS:
- acid was needed.
- base was needed.
Here's how I want to continue it:
acid was needed.