Which of the following has been proved to transmit HIV

A．He lost the final chance to win a championship.
B．He was knocked out during one contest.
C．He broke a bone in the wrist during a match.
D．He was awarded with a $1.5 million house.

A．the political circle will offer the help to the high schools.
B．giving a presentation is beneficial to students.
C．teaching methods have to be changed.
D．students are afraid to talk to strangers.