[Q]: How does the sentence end?

The Ukulele is being taught to Matthew by Justin in class. 
OPTIONS:
- Matthew must be the person learning.
- Justin must be the person learning.

[A]: Matthew must be the person learning.
QUES: Continue writing.

The navy moved its base from the island to the harbor, as the 

OPTIONS:
- island was an impenetrable strategic position.
- harbor was an impenetrable strategic position.
+++++++++
ANS: harbor was an impenetrable strategic position.
Problem: How does the sentence end?

Bob's new writing journal would not fit into his old backpack, the 
OPTIONS:
- backpack was too large.
- journal was too large.
Answer: journal was too large.
sentence: Robert knew nothing abut them but tried to fix his washer while Dennis was very knowledgeable but lazy.  OPTIONS:
- Robert couldn’t fix the washer.
- Dennis couldn’t fix the washer.
complete: Robert couldn’t fix the washer.
Makeup was a good use of money thought Joel, but not Donald, as 
OPTIONS:
- Joel enjoyed the artistry involved.
- Donald enjoyed the artistry involved.
Joel enjoyed the artistry involved.
Problem: Continue the following story.

For her friend's birthday, Janel was deciding between knitting her a sweater or buying her a nice watch. She chose the 
OPTIONS:
- sweater because it was more expensive.
- watch because it was more expensive.
Here's how I want to continue it:
watch because it was more expensive.