The part of a word that modifies a word's meaning that consists of a letter, a syllable, or several syllables and is attached to a word's beginning is a(n)

Prefix

Explanation:

A Prefix is defined as a morpheme or the part of the word that is added to the beginning of a root word to modify its meaning. This element of the word usually consists of 'a letter, a syllable, or several syllables' which primarily functions to either modify or revise the meaning of the base word. For example, if we place the prefix 'un-' before the base word 'happy', it becomes the antonym of the word and means 'not happy' while the prefix 'semi-' alters the meaning of the word by making it half like if 'semi-' is placed before circle, it means 'half circle.'

the maximum speed limit is 55 mph on a two-lane undivided highway and for vehicles towing trailers.

the answer:

in the first part of the story running is all that matters to squeaky. running gives her confidence and defines who she is. at the beginning of the story she says that other kids call her mercury because she runs very fast. in the text she refers to herself as "miss quicksilver".

the line that provides the best evidence that squeaky has self-confidence is

" and i continue with my breathing exercise, strolling down broadway toward the ice cream man on 145th with not a care in the world cause i am miss quicksilver herself".