About one third of the population in Beijing and Shanghai ______ netizens, but in poorest areas, only three or four percent ______ online.

In this hotel, the bread and butter ______served for breakfast. Meanwhile, a knife and fork _____very useful for a foreigner.

The number of people invited ______ fifty, but a number of them ____ absent for different reasons. 

Grammar mistakes of this kind _____ widely among Chinese students. 

Either you or one of your students ________ to attend the meeting that is due tomorrow.