Problem: How does the sentence end?

We returned the drill and opted to purchase a hammer, since the 
OPTIONS:
- drill was conducive to our building project.
- hammer was conducive to our building project.
Answer: hammer was conducive to our building project.

Problem: How does the sentence end?

The plank James intended to break the limestone with keeps breaking because the 
OPTIONS:
- limestone is harder.
- plank is harder.
Answer: limestone is harder.

Problem: How does the sentence end?

At the high school, Rebecca is better at talking to girls than Laura because 
OPTIONS:
- Rebecca is smoother.
- Laura is smoother.
Answer: Rebecca is smoother.

Problem: How does the sentence end?

We left the boat in the dock and took the barge instead, as the 
OPTIONS:
- boat had a easy time on the wavy ocean.
- barge had a easy time on the wavy ocean.
Answer:
barge had a easy time on the wavy ocean.