The World Health Organization gave a warning to the public without any______when the virus of H1N1 hit Mexico in April, 2009.
"Can you read?" Mary said to the notice.
English is a language ______ in many countries.
Most of the artists ______ to the party 'were from South Africa.
Do you know the boy _______ under the big tree?
The computer centre, ______ last year is very popular among the students in this school.