Choose the correct words. in the past,blind people (1) couldn't/mustn't read books-other people (2) must/had to read to them.that changed with the invention of braille.now,blind people (3) can/have to read any book they want,so they (4) mustn't/don’t have to depend on other people.they just (5) can’t/have to learn the braille alphabet.people who (6) can’t/must see well can also listen to audio books.