（1）
What is the common belief about our brain's processing speed?
A . It reaches its peak at the age of 20.B . It doesn't decrease before 40.C . It remains constant until 60.
（2）
What was the age range of the people included in the study?
A . From 10 to 60.B . From 20 to 80.C . From 10 to 80.
（3）
Why do older people make decision more slowly according to Dr. von Krause?
A . They become more careful.B . They process information slower.C . They need more time to get information.
（4）
What benefit can people get from the study?
A . It may help increase the mental processing speed.B . It may improve people's ability to concentrate.C . It may contribute to the research on diseases.
