What's an author's purpose? Abraham Lincoln's birthday is on February 12th. He was our 16th President. He is remembered for freeing the slaves.

answer; (d) i believe the best answer is ; ///people said that man could not fly, but in 1903, orville and wilbur wright made the first sustained powered flight in a heavier- than-air machine;

i cannot see any of the options                                                          

sentence lenght varies according to word choice.you select which word to use and that will require to use other expressions that collocate with the word chosen.sentence length will vary   according to the choice of words you make to express your ideas.