Zoos: present perfect com since (B1)
Modern zoos ___ enormously since the 1980s. Fifty years ago, most animals lived in small concrete cages with iron bars, and visitors came only to look at them. Today many zoos work as conservation centres: they protect species that have almost disappeared in the wild and they send young animals back to their natural habitat. Critics still argue that no cage can replace a forest, and that argument is serious. Even so, for some species a well-managed zoo has become the last safe place on the planet.
Fonte: English for ALL (texto original).
Assinale a alternativa que completa corretamente a lacuna do texto.
- A) has changed
- B) changed
- C) are changing
- D) have changed
- E) were changing