Question

sort the words by their vowel sounds.
glue rule mute flute due sunk
short u long u

Explanation:

To sort the words by vowel sounds:

• Short "u" sound: "sunk" (pronounced /sʌŋk/ with short u).
• Long "u" sound: "glue" (/ɡluː/), "rule" (/ruːl/), "mute" (/mjuːt/), "flute" (/fluːt/), "due" (/djuː/) all have long u (or related long vowel) sounds.

Answer:

Short u: sunk
Long u: glue, rule, mute, flute, due