When a researcher use grounded theory practice in collecting data, and categorizes data into patterns as the primary basis for organizing and reporting results, he is doing______.

A. Today’s children sleep less than those in the 19th century.
B. Children don’t get enough sleep nowadays.
C. Children always sleep less than recommended.
D. There is a gradual decline in the sleeping time recommended and taken by children.

A. the dancing girls are all very beautiful
B. the girls come from all over the world
C. the two tallest girls are the outstanding dancers
D. the girls’ performance is very successful