A group of black boys in a classroom setting wearing white shirts , listening to a speech about UNICEF .
It is impossible that a group of high school students hear about the advantages of donating to UNICEF .
It is probably the case that a group of high school students hear about the advantages of donating to UNICEF .
It is impossible that a group of high school students hear about the advantages of donating to UNICEF .
A group of high school students hear about the advantages of donating to UNICEF .