Final answer:
The word that best describes the first two line endings of the poem is 'end-stopped' because each line finishes with a pause indicated by punctuation or the end of a phrase.
Step-by-step explanation:
The first two line endings of the poem "roses are red, and violets are blue," can best be described as end-stopped. This is because each line concludes with either a form of punctuation or a complete phrase, which induces a natural pause in the poem's reading. End-stopped lines are characteristic of many traditional forms of poetry, where each line is syntactically independent from the following one. In contrast, enjambed lines do not end with a punctuation mark and the sentence or clause continues onto the next line. The use of enjambment or end-stopping has a significant effect on the poem’s rhythm and can impact the way it is read and understood.