阅读理解。         
        Different weather makes people feel different. It influences (影响) health, intelligence (智力) and
feelings.      
         In August, it is very hot and wet in the southern part of the United States. People there have heart trouble
and other kinds of health problems during this month. In the Northeast and the Middle West, it is very hot at
some times and very cold at other times. People in these states have more heart trouble after the weather
changes in February or March.
         The weather can also influence intelligence. For example, in a 1983 report by scientists, IQ (智商) of a
group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10%
lower. The wind can help people have more intelligence. Very hot weather, on the other hand, can make it lower. Students in many schools of the United States often get worse on exams in the hot months of the year (July
and August).Weather also has a strong influence on people's feelings. Winter may be a bad time for thin people.
They usually feel cold during these months. They might feel unhappy during cold weather. But fat people may
have a hard time in hot summer. At about 18℃, people become stronger.
          Low air pressure (气压) may make people forgetful. People leave more bags on buses and in shops on
low-pressure days. People feel best at a temperature of about 18℃.
          Are you feeling sad, tired, forgetful, or unhappy today? It may be the weather's problem.

A. hot and cold weather influences all people in the same way
B. weather influences people's behaviour
C. IQ changes when weather changes
D. people feel good on low pressure days