Sentence 1: Kara was shoveling the driveway. 
 Sentence 3: Still she shoveled, scoop after scoop 
 Sentence 4:  Kara looked back and made a plaintive gasp of despair 
 Sentence 5:  The snow had already covered her tracks 
 Option 1: She struggled to breathe in the cold air. 
 Option 2: She finished quickly since the snow had stopped.