My father, together with some of his old friends, _________there already.

The number of the students in our school _________ 600, but a number of students _________ living in the school.

Above one third of the population in Beijing and Shanghai      netizens, but in poorareas, only three or four percent        online.

One of Marx’s works _____written in English in the 1860s.

According to the recent regulation, it is required that any chemical plant that_______ along the river _______ to build a recycling center for the waste.