1. ?
    1. a
    2. b
    3. c
    4. d
  2. ?
    1. a
    2. b
    3. c
    4. d
  3. ?
    1. a
    2. b
    3. c
    4. d
  4. ?
    1. a
    2. b
    3. c
    4. d
apick up trash
bsave water
cbuy and sell used items
duse my own cup
e.g.I ride my bike to school every day.