Tenses and Sentence Rephrasing Quiz

Over the past decade, the government __________ (introduce) several laws to reduce air pollution.

Environmentalists __________ (campaign) for cleaner oceans since the 1990s.

The global temperature __________ (rise) steadily due to climate change.

Scientists __________ (study) the effects of deforestation for many years.

Many species __________ (become) endangered because of habitat destruction.

By the time the rainforests were destroyed, thousands of species __________ (already/disappear).

Before the city enacted recycling policies, people __________ (not/bother) to sort their waste.

When the fire broke out in the forest, firefighters __________ (try) to control the situation for hours.

They __________ (not/realize) the harmful effects of plastic waste until it was too late.

Before the cleanup operation started, volunteers __________ (collect) rubbish for several hours.