A number of students ______ playing on the ground but I don't know what the exact number______.

—Lydia, what did our head-teacher say just now? —Every boy and every girl as well as the teachers who _____ to lead the group _____ asked to be at the school gate before 6:30 in the morning.

Every possible means _____ to prevent the air pollution, but the sky is still not clear. 

Either they or Paul ______ to go to Beijing in 2014.

Clearly, development aid together with food ______ the long-term solution to the problem of poverty.