A) Humans will never travel to planets around even the nearest stars
Maybe one day, in hundreds of years, technology would be advanced enough for us to get to such planets!
Are the basic types of words that English has. Most grammar books say that there are eight parts of speech: nouns, verbs, adjectives, adverbs, pronouns, conjunctions, prepositions and interjections.
The tone is most likely hopeful, but I could be wrong.