Choose the correct answer.  

_______ we act now or not, climate change will continue to affect future generations.

Choose the correct answer.  

Nuclear, wind, and solar power are _______ energy sources.

Choose the correct answer.  

In this zoo, some scientists are trying to _______ some species that are seriously endangered.

Choose the correct answer.  

_______ action earlier, the damage to coastal ecosystems would have been much less severe.

Choose the correct answer.  

If factories _______ proper filters, they wouldn’t have released so many harmful gases into the air.

Choose the correct answer.  

_______ people are choosing to support environmental charities through fundraising events.

Choose the correct answer.  

The less smoke is released into the air, the _______ the atmosphere becomes.

Choose the correct answer.  

_______ the environmental protection project, the local river would have remained heavily polluted.