Problem: How does the sentence end?

His calculation was off, so he used a calculator instead of working it on a piece of paper. The 
OPTIONS:
- calculator was fast.
- paper was fast.
Answer: calculator was fast.

Problem: How does the sentence end?

Vocal lessons from Laura really helped Angela with their singing, since 
OPTIONS:
- Laura was a good student.
- Angela was a good student.
Answer: Angela was a good student.

Problem: How does the sentence end?

Samuel could really smell the wet dog on the furniture of the rental, whereas Matthew couldn't despite  
OPTIONS:
- Samuel having a stronger sense of smell.
- Matthew having a stronger sense of smell.
Answer: Matthew having a stronger sense of smell.

Problem: How does the sentence end?

Kathy's foot was swollen, so she took off the bandage and tried some medicine, because the 
OPTIONS:
- bandage was making it hurt more.
- medicine was making it hurt more.
Answer:
bandage was making it hurt more.