QUES: Continue writing.

Rebecca was instructing Katrina on how to ski because 
+++++++++
ANS: Katrina was a student on the mountain.


QUES: Continue writing.

Mary scrubbed the tile floor but thankfully didn't need to clean the toilet, because the 
+++++++++
ANS: floor was filthy.


QUES: Continue writing.

Elena had come to the end of the line although Monica was at the start. 
+++++++++
ANS: Elena was finishing.


QUES: Continue writing.

In the Winter, Craig never gets sick, but Jason always has a cold. 
+++++++++
ANS:
Jason has a frail immune system.