Answer:
In the line "How sweet I roamed from field to field", these are the stressed: sweet/roamed/field (2), and these are the unstressed syllables: how/I/from/to.
Step-by-step explanation:
(') = CAPS LOCL
(U) = lower case
how SWEET i ROAMED from FIELD to FIELD
Those are stressed because they have a strong accent, it relates to the way we pronounce the words, some are stressed or accented, some others are "light".