What is the chemical formula for hydrochloric acid?​

HCI is the formula for hydrochloric acid

#1  sara was always tasked with selecting birthday presents for her friends and family because everyone admired her  impeccable taste. 

impeccable (adj): perfect, flawless

#2  they moved to the united states many years ago, but their  insular  attitudes made it difficult for them to socialize. 

insular (adj): isolated; separate

#3  the professor explained the  semantic  relationship between the two nouns used in the sentence. 

semantic (adj): related to words or the meanings of words 

happy to : )

"the tune the he might never know again." this part build anticipation. dexter got extremely happy by the piano tune. he could see what he was living at that moment in his life throught this feeling. the reader might want to learn more about his happy life. in fact, he called it a state of   'ecstasy'. the fact that he had got in a mood of intense appreciation and that everything about him was extremely bright and glamorous might lead the reader to feel that this state of happiness may not last long. the two parts from the excerpt that exemplify the anticipation are: " the sound of the "; " it was a know again."