13. The audience _____________ by the performing animals at present.
are being amused
4. This river (polluted/were polluted) by the factories located on its banks.
were polluted
8. A cobra (can kill/can by killed) an adult with just its one bite.
can kill
12. The snow _____________ the mountain right now.
is covering
6. Natural resources (will used/will be used) up in the next few decades.
will be used up
10. In my country, elephants (have protected/have been protected) very seriously.
have been protected
1. Deforestation (should stop/should be stopped) right away.
should be stopped
3. People (are destroying/are being destroyed) forests without thinking of the future generation.
are destroying
7. We (were taking/ were being taken) to the zoo by our teacher.
were being taken
14. A whale __________ birth to its young only once every two or three years.
gives
11. Rice _________ all over Asia.
is grown
9. Eco-tourists (usually present/are usually presented) with the diversity of animals in the forest.
are usually presented
2. Thousands of trees (cut/are cut) down every day.
are cut
15. Hundreds of birds ____________ every day
are trapped
5. Scientists (have searched/have been searched) for alternative sources of energy for a long time.
have searched