Ответ:

  1. Bob ran into his old friend on his way home.
  2. If a burglar breaks into your house, you should hand over your valuables.
  3. The police are running after a robber.
  4. Many young people hang out at shopping centers at weekends.
  5. We ran out of milk, so I went to buy some.
  6. Beth is crazy about volleyball.
  7. There are a lot of activities to choose from.
  8. Keep your mobile phone switched on at night.