1. When he was walking down the street, he ran into Miss Fairchild.
(Does 'down' mean downward' or 'along' or 'on'?)
2. He was walking down the street.
3. he was walking along the street.
4. He was walking on the street.
5. He was walking up the street.
(Is #2 the opposite of #5? What does #2 mean? Is #2 Sentence 3 or Sentence 4? What is the difference? Thank you.)