A．To announce a medical breakthrough in curing ragweed allergies
B．To inform the public about the spread of a new type of an allergy
C．To recruit people who are willing to come forward for a medical cause
D．To provide the results of a test conducted by the research institute

A．They're most prevalent during the late summer months
B．Research about them has been ongoing for the entire summer
C．They have been the main public issue in recent months
D．They affect a great number of people living in hot climates

A．A number where interested people could call
B．The specific compensation each participant will receive for volunteering
C．The subject of the study being conducted
D．The conditions required for those who want to make a contribution