Answer:
<h2>To swell the gourd, and plump the hazel shells</h2>
Explanation:
Iambic pentameter is a type of metric line used in English poetry. Shakespeare used it in his words. It consist in using unstressed syllables follow it by a stressed one.
A remarkable example is the heart beat, one unstressed, the other stressed, like tum TUM ... tum TUM ... tum TUM... tum TUM... tum TUM...
It's used in 5 times, that's why is called PENTAmeter.
So, the line to swell the gourd, and plump the hazel shells, shows this iambic form.
Another line could be a Shakespeare's one:
<em>When I do count the clock that tells the time</em>