I don’t think ________ possible to master a foreign language without much memory work.

Debbie is growing fast. She is even ________ than her mother.

Vitamin D helps our bodies make a special chemical, and this special chemical, ______, affects our brains, making us feel happy.[ ]

12．On Oct. 23 , 2008 there was the 6oth sports meet,_____our students took an active part in.

Father told me_____ football in the street.