Cause and appear because these words need to be singular since the other words are plural
<span>Read the Aesop's fable of The Wolf and the Lamb from this famous book. ... "There's my supper," thought he, "if only I can find some excuse to seize it." Then he ...</span><span>
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Early poems were written in meter first of all to distinguish them from prose, from everything written like a text.
Also, usually these poems were sung as songs, using various musical instruments, so meter was important when it came to rhythm.