Last year, some groups of students in their community (社区) made a survey about “How do people spend their free time? ” The following diagrams(图表) show some results of it:
Diagram (1): Hours for people of different ages who surf the Internet in a week.

Diagram (2): Different days people go to the library. (library attendance出席)

Diagram (3): Different programs people like.

People aged     spend the most time surfing the Internet every week.

A．7—16

B．17—30

C．31—55

D．over 56

How many people go to the library on Saturdays?

A．About 20%.

B．About 40%.

C．Over 60%.

D．More than 80%.

The three diagrams show us the results of a survey about    .

A．what people do every day	B．people’s different habits
C．people’s different lifestyles	D．how people spend their free time