Reclaiming Urban Rivers — IELTS Listening Answers

“However, as cities grew to over a million inhabitants, the impact on the rivers became more serious. In addition, other types of pollution increased, as factories were built beside the river and discharged their waste materials into the water”

Pollution worsened as factories were built beside the river and discharged waste, so the source is 'factories'.

“As recently as 1957, scientists at London's Natural History Museum declared that the River Thames was dead in biological terms, as the water was too filthy to support any kind of life”

In 1957 scientists declared the Thames dead in biological terms, so the adjective needed is 'dead'.

“These days you can see seals swimming in the water, and recently people had to try to rescue a whale, which had got lost and swum up the river from the sea by mistake”

People had to rescue a whale that had swum up the river by mistake, so the animal is 'whale'.

“Warehouses that were once used for storing goods are now being converted into expensive restaurants and also into apartments with river views”

Warehouses are being converted into restaurants and apartments with river views, so the housing is 'apartments'.

“an architect has plans to revitalise the banks of the river and to make a park there which can provide facilities for sports as well as a natural environment for relaxing in”

The architect plans to make a park there with sports facilities, so the gap takes 'park'.

“It’s been proposed that facilities could be provided for displaying projects related to various kinds of art that have been produced by local people, for example”

Facilities could display projects related to various kinds of art produced by local people, so the subject is 'art'.

“In the city of Paris, During the summer months of July and August, all the traffic is banned from the roads by the sides of the river, and the banks are transformed into beaches”

In Paris the banks are transformed into beaches during July and August, so the plural noun is 'beaches'.

“Already, more than two billion passengers use the ferry to travel in cities around the world, like Istanbul, San Francisco and New York, and these numbers are set to rise further”

More than two billion passengers use the ferry in cities around the world, so the transport is 'ferry'.

“When the barge docks at the riverside the parcels could be taken the last few kilometres to their final destination on cargo bikes, electric ones of course”

Parcels could cover the last kilometres on cargo bikes, so the plural noun is 'bikes'.

“this is already happening in the Dutch city of Amsterdam, and in future the final stage could even be carried out by drone, although at present this isn't allowed”

The final stage could be carried out by drone, though this is not allowed at present, so the gap takes 'drone'.