Ответ:

  1. You are on your bike. You should wear a helmet.
  2. You shouldn’t play very fast on the road.
  3. You are in a car. You should ask for directions.
  4. You shouldn’t use your phone when you cross the street.
  5. There are a lot of cars. You should be careful.
  6. You shouldn’t ride your bike very fast near other people.

Ответ: 1) should; 2) shouldn’t; 3) should; 4) shouldn’t; 5) should; 6) shouldn’t.