[Q]: How does the sentence end?

Dennis was less impressed with the crystals than Jason, because 
OPTIONS:
- Dennis was seeing the crystals for the tenth time.
- Jason was seeing the crystals for the tenth time.

[A]: Dennis was seeing the crystals for the tenth time.


[Q]: How does the sentence end?

The ball smashed through the glass while the rock bounced off, since the 
OPTIONS:
- ball was an effective missile.
- rock was an effective missile.

[A]: ball was an effective missile.


[Q]: How does the sentence end?

Matthew put copper insulation in their pipes while Robert didn't, so 
OPTIONS:
- Matthew 's pipe were dirty.
- Robert 's pipe were dirty.

[A]:
Robert 's pipe were dirty.