Qual e a função das palavras destacadas

One of the most important qualities of a group leader

Which detail from the diary of a young girl supports the idea that anne’s voice is optimistic? “at three o'clock . . the doorbell rang. i didn't hear it, since i was out on the balcony, lazily reading in the sun.” “so much has happened it's as if the whole world had suddenly turned upside down.” “the first thing i stuck in was this diary, and then curlers, handkerchiefs, schoolbooks, a comb and some old letters.” “it may be damp and lopsided, but there's probably not a more comfortable hiding place in all of amsterdam.”

What is a verb infinitive and what does is mean to conjugate a verb?