Read the text. Choose the correct form of the words in the gaps.

Schools in Australia
Australia is a big country, but it ... \(have\) a population of only 20 million people.
Some ... \(family\) live on farms which are hundreds of kilometres away from a town or a city. Children from ... \(this\) families can’t travel to school every day. So teachers prepare lessons and send ... \(they\) to students by e-mail. The students work on these lessons Monday to Friday and send ... \(they\) homework to school once a week.
Several times a year a teacher ... \(visit\) every student at home. The teacher helps students with their work and ... \(discuss\) problems. The teacher often stays for the whole day at the ... \(student\) house.