Why do people highlight stuff in books, or texts?

Which sentence uses all its nominative case pronouns correctly? a we live on the same street b them and rachel are good skaters. c the redskins fans in the family are fred and me d have joanne and him played tennis together before?

The man took strong sharp sudden bites, just like the dog. the figurative language in this excerpt serves to a. give the convict animalistic qualities. b. provide a relatable example of how the convict ate. c. set a scary mood. d. use alliteration to catch the reader's attention.

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances. in four to six sentences, explain how the structure of the first amendment supports equal weight of each freedom it guarantees.