Traffic creates a great deal of p_________ in many big cities.
There was a c_________ of over 1,000 people in the street.
It’s a big i__________ city where they make cars and electronic      equipment.
Be careful! It’s d__________ to walk around town late at night.
It’s a very a__________ town with a lot of beautiful buildings.
In some countries, it is __________(不安全) to drink the water because it is dirty.
When studying children and other young animals, we can see the striking _________(相似) in their behaviour.
It is unbelievable that there are still many people in rural areas living below _________(贫困) line.
It is reported in the paper that many _________(慈善机构)around the world have sent aid to the tsunami-hit countries.
  The policeman said to the young man,＂please give me your precise _________(所在地).＂