A study shows that walking fast in your old age is a ______ that you will live a long life.

People who are infected with HIV are often looked down upon because social _____ against the disease runs so deep.

Jim is good at English. He often gives me some useful ____on how to read English.

－Do you have anyone particular in______for the job?－In my opinion, Tom is the right person.

  —Nowadays the doctors are trying their best to reduce the people’s fear__________ they would be affected by the present disease called “Bird Flu （禽流感）”.