Question

read the incomplete quatrain. the train recedes; a lonely whistle blows i raise my hand to wave one last good - bye my tears begin to fall as distance grows which line completes the quatrains \abab\ rhyme scheme? and both the train and i emit a sigh and in its wake my heart begins to ache and i am left alone without my dreams and i am left to ponder thoughts of us

Explanation:

In an "abab" rhyme scheme, the first and third lines rhyme, and the second and fourth lines rhyme. The first line ends with "blows" and the third line ends with "grows". We need a fourth - line ending that rhymes with "bye". "Sigh" rhymes with "bye" (both have the /aɪ/ sound). "Ache" has an /eɪ/ sound, "dreams" has an /iːmz/ sound, and "us" has an /ʌs/ sound, none of which rhyme with "bye".

Answer:

And both the train and I emit a sigh