[Q]: How does the sentence end?

In the garden, Betty is having more success with growing flowers than Kayla due to 

[A]: Betty using a strong fertilizer.


[Q]: How does the sentence end?

Nick decided to leave the band, while Eric remained, because 

[A]: Eric was happy with the other members.


[Q]: How does the sentence end?

Megan planned to pass her pencil over to Natalie shortly, as 

[A]:
Megan was just about to complete her writing.