I. Choose the active or passive form of the verb in brackets for each sentence. 1. Deforestation (should stop / should be stopped ) right away. 2. Thousands of trees (cut / are cut) down every day. 3. People ( are destroying/ are being destroyed) forests without thinking for the future generation. 4. This river (polluted / were polluted) by the factories located on its banks. 5. Scientists ( have searched / have been searched ) for alternative sources of energy for a long time. 6. Natural resources (will use/will be used) up in the next few decades. 7. We ( were taking/ were being taken) to the zoo by our teacher that day. 8. A cobra ( can kill/ can be killed) an adult with just its one bite. 9. Ecotourists ( usually present / are usually presented ) with the diversity of animals in the forest. 10. In my country, elephants ( have protected/ have been protected) very seriously.